AN AMERICAN NATIONAL STANDARD

A N A M E R I C A N N A T I O N A L S T A N D A R D

Unified Inch Screw Threads(UN and UNR Thread Form)

ASME B1.1-2003[Revision of ASME B1.1-1989 (R2001)]

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A N A M E R I C A N N A T I O N A L S T A N D A R D

UNIFIED INCHSCREW THREADS

(UN and UNR Thread Form)

ASME B1.1-2003[Revision of ASME B1.1-1989 (R2001)]

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Date of Issuance: September 30, 2004

The 2004 edition of this Standard is being issued with an automatic addenda subscription service.The use of addenda allows revisions made in response to public review comments or committeeactions to be published as necessary. This Standard will be revised when the Society approves theissuance of a new edition.

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The American Society of Mechanical EngineersThree Park Avenue, New York, NY 10016-5990

Copyright © 2004 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERS

All rights reservedPrinted in U.S.A.

CONTENTS

Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viCommittee Roster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii

1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Unified Screw Thread Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.3 UN and UNR Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.4 Interchangeability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.5 Designations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.6 Reference Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.7 Acceptability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.8 Reference Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.9 Units of Measure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.10 Federal Government Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2 Screw Thread Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.2 Basic Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.3 Design Profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.4 Formulas and Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

3 Screw Thread Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.1 Thread Series Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2 Order of Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.3 Coarse-Thread Series Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.4 Fine-Thread Series Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.5 Extra-Fine-Thread Series Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.6 Constant-Pitch Thread Series Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.7 Fine Threads for Thin-Wall Tubing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4 Screw Thread Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364.1 Thread Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364.2 Combinations of Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5 Screw Thread Allowance and Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365.1 Allowance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365.2 Pitch Diameter Tolerance, All Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365.3 Special Lengths of Engagement, LE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375.4 Minor Diameter Tolerance and Allowance for External Threads . . . . . . . . . . 545.5 Major Diameter Tolerance for Internal Threads . . . . . . . . . . . . . . . . . . . . . . . . . . 545.6 Minor Diameter Tolerance and Length of Engagement for Internal

Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555.7 Disposition of Allowance and Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555.8 Formulas for Allowance and Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555.9 Lead and Flank Angle Tolerances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585.10 Coated or Plated Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585.11 Circular Runout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

6 Screw Thread Designation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 586.1 Basic Method of Designating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

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6.2 Method of Designating Coated Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 616.3 Method of Designating Left-Hand Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 626.4 Method of Designating UNS Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 626.5 Designations for Other Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 626.6 Method of Designating Threads Having Special Length of

Engagement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 636.7 Method of Designating Threads Having Modified Crests. . . . . . . . . . . . . . . . . 63

7 Dimensional Accommodation of Coating or Plating for 60-deg Threads . . . . . . . . . . 647.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 647.2 Material Lifts for Coated Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 647.3 Dimensional Effects of Coating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 647.4 External Thread With Allowance Available for Coating . . . . . . . . . . . . . . . . . . 647.5 External Thread With No Allowance for Coating . . . . . . . . . . . . . . . . . . . . . . . . 647.6 Internal Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 667.7 Electrodeposited Coatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 677.8 Other Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

8 Standard Series Threads (UN/UNR) and Limits of Size for Standard Seriesand UNS/UNRS Series Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

8.1 Standard Series. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 678.2 Limits of Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 678.3 Formulas for Limits of Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 678.4 Example of Calculations From Formulas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

9 Lead and Angle Tolerances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 689.1 Lead and Flank Angle Acceptance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

10 Formulas and Symbols for Thread Form . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6910.1 Thread Form Formulas and Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

11 Tables of Basic Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7011.1 Table Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7011.2 Thread Series. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Figures1 Basic Profile for UN and UNR Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Disposition of Diametral Tolerances, Allowance, and Crest Clearance for

Unified Inch Screw Thread Classes 1A, 2A, 1B, and 2B . . . . . . . . . . . . . . . . . . . . . 43 Disposition of Diametral Tolerances and Crest Clearances for Unified Inch

Screw Thread Classes 3A and 3B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Ratio of Pitch Diameter Change to Thickness of Coating on 60-deg

Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 655 Effect of Electrodeposited Coatings on 60-deg External Threads . . . . . . . . . . . . . . . 666 Application of General Thread Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Tables1 Standard Series Threads (UN/UNR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Limits of Size for Standard Series Threads (UN/UNR) . . . . . . . . . . . . . . . . . . . . . . . . 83 Allowable Variations in Lead and Equivalent Change in Functional

Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 384 Increments in Pitch Diameter Tolerance — Class 2A . . . . . . . . . . . . . . . . . . . . . . . . . . 565 Thread Form Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 596 Basic Dimensions for Coarse-Thread Series (UNC/UNRC) . . . . . . . . . . . . . . . . . . . . 727 Basic Dimensions for Fine-Thread Series (UNF/UNRF) . . . . . . . . . . . . . . . . . . . . . . . 738 Basic Dimensions for Extra-Fine-Thread Series (UNEF/UNREF) . . . . . . . . . . . . . . . 749 Basic Dimensions for 4-Thread Series (4-UN/4-UNR) . . . . . . . . . . . . . . . . . . . . . . . . . 75

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10 Basic Dimensions for 6-Thread Series (6-UN/6-UNR) . . . . . . . . . . . . . . . . . . . . . . . . . 7611 Basic Dimensions for 8-Thread Series (8-UN/8-UNR) . . . . . . . . . . . . . . . . . . . . . . . . . 7712 Basic Dimensions for 12-Thread Series (12-UN/12-UNR) . . . . . . . . . . . . . . . . . . . . . . 7913 Basic Dimensions for 16-Thread Series (16-UN/16-UNR) . . . . . . . . . . . . . . . . . . . . . . 8114 Basic Dimensions for 20-Thread Series (20-UN/20-UNR) . . . . . . . . . . . . . . . . . . . . . . 8315 Basic Dimensions for 28-Thread Series (28-UN/28-UNR) . . . . . . . . . . . . . . . . . . . . . . 8416 Basic Dimensions for 32-Thread Series (32-UN/32-UNR) . . . . . . . . . . . . . . . . . . . . . . 8517A Outline Guide for Determining Limits of Size of External Threads . . . . . . . . . . . . 8617B Outline Guide for Determining Limits of Size of Internal Threads . . . . . . . . . . . . . 8618A Examples of External Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8718B Examples of Internal Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9019 Allowable Variation in 30 deg Basic Half Angle of External and Internal

Screw Threads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9220 General Symbols. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Nonmandatory AppendicesA Terminology and Identification of Unified Inch Screw Threads . . . . . . . . . . . . . . . . 95B Thread Strength Design Formulas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97C Unified Inch Screw Threads — Metric Translation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98D Special Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134E Changes to ASME B1.1-1989 Tables 3A and 3B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

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FOREWORD

This Standard is the outgrowth of and supersedes previous editions that were published asB1-1924, B1.1-1935, B1.1-1949, B1.1-1960, B1.1-1974, B1.1-1982, and B1.1-1989. Throughout suchdevelopment, special attention has been given to the practical aspects of thread standardization,and many details of the current Standard result from studies and tests based on user problems.For example, there was disclosed the need for free assembly in high-production industries andthe desirability of making some provision for threads that require a coating. The tolerance classes2A/2B were developed to meet these two major requirements as well as to provide a generalstandard for externally and internally threaded fasteners. Thread symbols and nomenclaturewere changed to be expressed according to ASME B1.7. Thread acceptability now refers toASME B1.3.

This issue includes the following changes to ASME B1.1-1989:(a) The revision of some of the values in Table 2. These revisions are the result of the application

of the consistent eight place decimal and rounding rules established in ASME B1.30-1992 thatwere mandated for use in all new and future revisions of ASME B1 documents. ASME B1.30 wasdeveloped under the direction of the B1 Committee as the basis for rounding of decimal valuesassociated with the computation of screw thread dimensions. Using the thread calculation formu-las in paras. 5 and 8 of this document and following the rounding rules of B1.30 all parties usinga calculator or standard computer spreadsheet program will derive precisely the same values.

Table E-1 of Nonmandatory Appendix E identifies the thread sizes in Table 2 that have beenrevised and lists the dimensions from the ASME B1.1-1989 standard. The majority of the dimen-sional changes are within ± 0.0001 in.

Paragraph 8.2.1 states that both the values in Tables 2 and E-1 should be considered acceptableuntil a future revision of this standard makes the values in Table 2 the only acceptable values.

(b) Former Table 3B has been moved to Nonmandatory Appendix D. This table providescalculated values for various UNS (Unified Specials). ASME B1 strongly urges the adoption ofthe standard thread sizes in Table 2 whenever possible instead of those listed in Table D-1.

(c) Former Tables 20 through 30 have been eliminated because the allowances and tolerancescontained in them was determined to be redundant with data provided in Table 2.

(d) Former Tables 31 through 40 have been moved to Nonmandatory Appendix D and wererenamed Tables D-2 through D-11. These tables were used in the past for the quick calculationof special threads. In some cases the derived values resulted in values that differ from thosederived by use of the formulas in paras. 5 and 8 of ASME B1.1. All future special threads shouldbe based on calculations in paras. 5 and 8 in this document using the rounding rules in ASMEB1.30 to ensure uniformity and consistency.

(e) All references to percent of thread engagement have been eliminated from this document.Past changes in the thread form designation of the “basic” thread height from 0.750H to 0.625Hconfused the calculation of percent of thread engagement. This calculation has been used in thepast for threaded products users to determine drill size selection. It is now recommended thatusers select a drill size that will result in a hole size that lies between the maximum and minimumsize of the internal thread’s minor diameter shown in the tables included in this Standard.

(f) The definition of “functional diameter” has been included in this document and the termhas been added in Table 2 in the same column as “pitch diameter” since both characteristics havethe same limits of size.

(g) The effects of coating on threads have been explained in more depth in para. 7.The Unified Screw Threads Standard is an integrated system of threads for fastening purposes

in mechanisms and structures. Its outstanding characteristic is general interchangeability ofthreads, achieved through the standardization of thread form, diameter-pitch combinations, andlimits of size.

The Standard has as its original basis the work done more than a century ago by WilliamSellers in the United States and Sir Joseph Whitworth in Great Britain. Throughout the intervening

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years there have been many further developments and revisions, culminating in the system ofUnified Threads approved and adopted for use by all inch-using countries.

The achievements represented by ASME B1.1 in development, standardization, and unificationare the result of cooperation and coordination of many organizations, including The AmericanSociety of Mechanical Engineers, Society of Automotive Engineers, National Institute of Scienceand Technology (formerly National Bureau of Standards), Committee B1, the former NationalScrew Thread Commission, the former Interdepartmental Screw Thread Committee, British Stan-dards Institution, Canadian Standards Association, and American National Standards Institute.

Unification of screw thread standards received its impetus from the need for interchangeabilityamong the billions of fasteners used in the complex equipment of modern technology and madein different countries. Equally important, however, are international trade in mechanisms of allkinds and the servicing of transportation equipment which moves from country to country. Thesehave made unification not only highly advantageous, but practically essential. In sizes 1⁄4 in. andlarger, complete unification of certain thread series and six tolerance classes was signaled by thesigning of an accord on November 18, 1948. Since that time, further unification has been extendedinto smaller sizes. Working through Technical Committee No. 1 of the International Organizationfor Standardization (ISO), the unified standard was adopted as an ISO inch screw thread standard,ISO 5864, parallel to the ISO metric screw thread system. Both systems have a common basicprofile. The standard was subject to Quadripartite Standardization Agreement (QSTAG) 247, inthe ABCA Army Standardization Program of America, Britain, Canada, and Australia.

Suggestions for improvement of this Standard will be welcomed. They should be sent to theAmerican Society of Mechanical Engineers at ASME International, Three Park Avenue, New York,NY 10016-5990, U.S.A.

ASME B1.1-2003 was approved by the American National Standards Institute (ANSI) on March27, 2003.

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ASME STANDARDS COMMITTEE B1Standardization and Unification of Screw Threads

(The following is the roster of the Committee at the time of approval of this Standard.)

OFFICERS

A. L. Barrows, ChairD. S. George, Vice Chair

R. L. Crane, Secretary

COMMITTEE PERSONNEL

G. L. Allen, L. S. Starret Co.A. L. Barrows, Kennametal — IPGM. H. Bernier, Standard Nut and BoltF. G. Calderone, Quality Systems ImplementersR. L. Crane, The American Society of Mechanical EngineersL. N. Dixon, Jr., General ElectricR. Dodge, Pennoyer-Dodge Co.G. A. Flannery, Mercury Gage Co.D. Skierski, Alternate, Mercury Gage Co.H. N. Frost, Defense Supply Center PhildelphiaJ. O. Gehret, Vermont Thread GageD. S. George, Ford Motor Co.J. R. Gervasi, Kerr Lakeside Inc.J. Greenslade, Greenslade & Co.J. Vance, Alternate, Greenslade and Co.R. J. Hukari, SPS TehnologiesL. C. Johnson, The Johnson Gage Co.D. D. Katz, Precision Fittings

SUBCOMMITTEE 1 — UNIFIED SCREW THREADS

A. L. Barrows, Chair, Kennametal — IPGD. Miskinis, Vice-Chair, Kennametal — IPGM. H. Bernier, Standard Nut and BoltM. Cox, Frank J. Cox Sales, Ltd.L. N. Dixon, Jr., General ElectricH. N. Frost, Defense Supply Center PhiladelphiaD. S. George, Ford Motor Co.J. R. Gervasi, Kerr Lakeside, Inc.J. Greenslade, Greenslade & Co.J. Vance, Alternate, Greenslade & Co.D. H. Honsinger, ConsultantR. J. Hukari, SPS TehnologiesL. C. Johnson, The Johnson Gage Co.J. M. Kane, Boeing

viii

R. P. Knittel, Leitech–U.S., Ltd.B. Larzelere, Deltronic Corp.L. L. Lord, Caterpillar, Inc.R. L. Tennis, Alternate, Caterpillar, Inc.M. H. McWilliams, PMC Gage, Inc.D. Miskinis, Kennametal–IPGW. R. Newman, ConsultantM. W. Rose, Southern Gage, Inc.W. A. Watts, Alternate, Southern Gage, Inc.E. Schwartz, ConsultantR. H. Searr, ConsultantB. F. Sheffler, Dresser-Rand Co.A. D. Shepherd, Jr., Emuge Corp.A. G. Strang, ConsultantR. D. Strong, General Motors Corp.A. F. Thibodeau, Swanson Tool Manufacturing Co.R. E. Vincent, Jr., General Plug Manufacturing Co.C. J. Wilson, Industrial Fasteners InstituteF. W. Akstens, Alternate, Industrial Fasteners Institute

D. D. Katz, Precision FittingsR. P. Knittel, Leitech — U.S., Ltd.B. Larzelere, Deltronic Corp.L. L. Lord, ConsultantW. R. Newman, ConsultantE. Schwartz, ConsultantR. H. Searr, ConsultantB. F. Sheffler, Dresser-Rand Co.J. D. Smith, Hi-Shear Corp.R. D. Strong, GM Vehicle Engineering Ctr.A. F. Thibodeau, Swanson Tool Manufacturing, Inc.R. E. Vincent, Jr., General Plug Manufacturing Co.C. J. Wilson, Industrial Fasteners InstituteF. W. Akstens, Alternate, Industrial Fasteners Institute

ASME B1.1-2003

UNIFIED INCH SCREW THREADS

(UN AND UNR THREAD FORM)

1 GENERAL

1.1 Scope

This Standard specifies the thread form, series, class,allowance, tolerance, and designation for unified screwthreads. (In order to emphasize that unified screwthreads are based on inch modules, they may be denotedunified inch screw threads.) Several variations in threadform have been developed for unified threads; however,this Standard covers only UN and UNR thread forms.

For easy reference, a metric translation of this Stan-dard has been incorporated as Nonmandatory Appen-dix C. Nonmandatory Appendices A through E containuseful information that is supplementary to the sectionsof this Standard.

1.2 Unified Screw Thread Standards

The standards for unified screw threads published inthis Standard are in agreement with formal standardsof the International Organization for Standardizationfor diameter-pitch combinations, designations, and tol-erances for 60 deg triangular form inch screw threads.Unified screw threads had their origin in an accordsigned in Washington, D.C., on November 18, 1948, byrepresentatives of standardizing bodies of Canada, theUnited Kingdom, and the United States, and have subse-quently superseded American National screw threads.

1.3 UN and UNR Screw Threads

UNR applies only to external threads; the differencebetween UN and UNR threads, in addition to designa-tion, is that a flat or optional rounded root contour isspecified for UN threads, while only a rounded rootcontour is specified for UNR threads.

1.4 Interchangeability

Unified (UN/UNR) and its predecessor, AmericanNational screw threads, have substantially the samethread form, and threads of both standards having thesame diameter and pitch are mechanically interchange-able. The principal differences between these standardsrelate to the application of allowances, the variation oftolerances with size, differences in the amounts of pitchdiameter tolerances for external and internal threads,and differences in thread designations. Unified inch and

1

ISO metric screw threads are not mechanically inter-changeable.

1.5 Designations

Unified thread sizes (specific combinations of diame-ter and pitch) are identified by the letter combination“UN” in the thread symbol. In the unified standards,the pitch diameter tolerances for external threads differfrom those for internal threads; for this reason the letter“A” is used in the thread symbol to denote an externalthread and the letter “B,” an internal thread. Where theletters “U,” “A,” or “B” do not appear in the threaddesignation, the threads conform to the outdated Ameri-can National screw threads. Details regarding threaddesignations are given in para. 6.

1.6 Reference Documents

The latest issues of the following documents form apart of this Standard to the extent specified herein.

When the following American National Standardsreferred to in this Standard are superseded by a revisionapproved by the American National Standards Institute,Inc., the revision should apply.

ASME B1.2, Gages and Gaging for Unified Inch ScrewThreads

ASME B1.3, Screw Thread Gaging Systems for Dimen-sional Acceptability — Inch and Metric Screw Threads

ASME B1.7, Nomenclature, Definitions, and Letter Sym-bols for Screw Threads

ASME B1.30, Screw Threads — Standard Practices forCalculating and Rounding Dimensions

ASME B47.1, Gage BlanksASME B94.11, Twist DrillsASME Y14.5, Dimensioning and Tolerancing

Publisher: The American Society of Mechanical Engi-neers (ASME International), Three Park Avenue, NewYork, NY 10016-5990; Order Department: 22 LawDrive, Box 2300, Fairfield, NJ 07007-2300

ISO 68, General Purpose Screw Threads — Basic Profile

Publisher: International Organization for Standardiza-tion (ISO), 1 rue de Varembe, Case Postale 56, CH-1211, Geneve 20, Switzerland/Suisse



ASME B1.1-2003 UNIFIED INCH SCREW THREADS

1.7 Acceptability

Acceptability of product threads shall be in accor-dance with ASME B1.3. Gages and gaging shall be inaccordance with ASME B1.2.

1.8 Reference Temperature

The reference temperature is 68°F for dimensionsdefined by this system.

1.9 Units of Measure

All dimensions in this Standard, including all tables,are in inches unless otherwise specified.

1.10 Federal Government Use

When this Standard is approved by the Departmentof Defense and federal agencies and is incorporated intoFED-STD-H28/2, Screw-Thread Standards for FederalServices, para. 2, the use of this Standard by the federalgovernment will be subject to all the requirements andlimitations of FED-STD-H28/2.

2 SCREW THREAD PROFILE

2.1 Scope

The basic profile and design profiles are defined inthis paragraph and are the basis of all thread dimensionsgiven in this Standard.

2.2 Basic Profile

The basic profile for UN screw threads is identical tothat for UNR screw threads and is shown in Fig. 1.Profile applies to an axial plane.

For reference, the basic profile for UN and UNR screwthreads is identical to that for ISO metric screw threadsshown in ISO 68.

2.3 Design Profiles

The design profiles define the maximum-material con-ditions for external and internal threads with no allow-ance and are derived from the basic profile. The designprofiles of both external and internal screw threads varyfrom the basic profile.

2.3.1 Design Profiles of External Threads. The designprofiles of external UN and UNR screw threads areincluded in Figs. 2 and 3. A flat root contour is specifiedfor UN threads; however, it is permissible to providefor some threading tool crest wear. Therefore, a roundedroot contour cleared beyond the 0.250P flat width of thebasic profile is optional. The rounded root also reducesthe rate of threading tool crest wear and improvesfatigue strength over that of a flat root thread.

(a) The root contour of external UNR screw threadsshown in Figs. 2 and 3 shall have a smooth, continuous,nonreversing contour with a radius of curvature not lessthan 0.10825318P at any point and shall blend tangen-tially into the flanks and any straight segment. At the

2

maximum-material condition, the point of tangencyshall be at a distance not less than 0.54126588P (0.625H)below the basic major diameter.

NOTE: The maximum full root radius is 0.14433757P, but this maybe exceeded when the root contour consists of a combination offlats and radii.

(b) The design profiles of external UN and UNR screwthreads have flat crests. However, in practice, productthread crests may be flat, or partially corner rounded.A rounded crest tangent at a 0.125P flat is shown as anoption in Figs. 2 and 3.

2.3.2 Design Profile of Internal Threads. The designprofile of the internal UN screw thread is included inFigs. 2 and 3 (there is no internal UNR screw thread).In practice, it is necessary to provide for some threadingtool crest wear; therefore, the root of the design profileis rounded and cleared beyond the 0.125P flat width ofthe basic profile.

2.4 Formulas and Symbols

The formulas and symbols pertaining to the basicprofile and the design profiles are given in para. 10.

3 SCREW THREAD SERIES

3.1 Thread Series Definition

Thread series are groups of diameter-pitch combina-tions distinguished from each other by the number ofthreads per inch applied to a series of specific diameters.There are two general series classifications: standardand special.

3.1.1 Standard Series. The standard series consistsof three series with graded pitches (coarse, fine, andextra fine) and eight series with constant pitches (4, 6,8, 12, 16, 20, 28, and 32 threads per inch). The standardseries is shown in Table 1. Limits of size are shown inTable 2. See para. 8 for limits of size.

3.1.2 Special Series. The special series consists of allthreads with diameter-pitch combinations that are notincluded in the standard series. When allowances andtolerances of special series threads are derived from uni-fied formulation as shown in para. 5, the threads aredesignated UNS or UNRS. If allowance and toleranceare not derived from unified formulation, the threadsare designated “SPL 60 degree Form.” See para. 6 fordetails of designation.

3.2 Order of Selection

Wherever possible, selection should be made fromTable 2, Standard Series — Unified Screw Threads, pref-erence being given to the coarse- and fine-thread series.Second choice; if the threads in the standard series inTable 2 do not meet the requirements of the design,

UNIFIED INCH SCREW THREADS ASME B1.1-2003

0.86602540P(H)

P

60 deg

30 deg

90 deg

Axis of screw thread

D bsc, d bsc

D2 bsc, d2 bsc

D1 bsc, d1 bsc

0.125P0.10825318P

(0.125H)

0.32475953P(0.375H)

0.54126588P(0.625H)

0.21650635P(0.25H)

0.250P

0.500P

0.500P

GENERAL NOTE: For standardization, values have been established based on a function of pitch, P. The thread valuesbased on a function of height, H, are used for reference only.

Fig. 1 Basic Profile for UN and UNR Screw Threads

special thread sizes should be selected from Table E-1 ofNonmandatory Appendix E and their limits calculatedusing the formulas in para. 8. The limits in Table D-1 ofNonmandatory Appendix D are for reference only andare not recommended for new applications.

3.3 Coarse-Thread Series Applications

The coarse-thread series (UNC/UNRC) is generallyused for the bulk production of screws, bolts, and nuts.It is commonly used in relatively low-strength materialssuch as cast iron, aluminum, magnesium, brass, bronze,and plastic, because the coarse-thread series providemore resistance to internal thread stripping than the fineor extra-fine series. Coarse-thread series are advanta-geous where rapid assembly or disassembly is required,or if corrosion or damage from nicks due to handlingor use is likely.

3.4 Fine-Thread Series Applications

The fine-thread series (UNF/UNRF) is commonlyused for bolts and nuts in high-strength applications.This series has less thread depth and a larger minor

3

diameter than coarse-thread series. Consequently, thin-ner walls are permitted for internal threads and morestrength is available to external threads than for coarse-thread series of the same nominal size. In order to pre-vent internal thread stripping, a longer length of engage-ment is required for fine-thread series than for coarse-thread series for thread materials of the same strengthlevels. However, for both fine- and coarse-thread series,length of engagement in tapped holes must be selectedto meet strength requirements. This also allows for fineradjustment in cases such as a slotted nut and cotter pinassembly.

3.5 Extra-Fine-Thread Series ApplicationsThe extra-fine-thread series (UNEF/UNREF) is used

particularly for equipment and threaded parts thatrequire fine adjustment, such as bearing retaining nuts,adjusting screws, etc., and for thin-wall tubing andthin nuts.

3.6 Constant-Pitch Thread Series ApplicationsThe various constant-pitch series (UN/UNR) with 4,

6, 8, 12, 16, 20, 28, and 32 threads per inch, given in




UNR contour, see para. 2.3.1(a)

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1/2 allowance (external only)

Basic form

0.041667P

0.125P UN (maximum) minor diameter of external

For UNR threads, this root is defined as a continuous rounded contour with a radius not less than 0.10825318P. For UN threads this root may be flat. See para. 2.3.1.

1/2 PD tolerance on internal

1/2 PD tolerance on external

1/2 allowance (external)

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1/2 tolerance on major diameter of internal

In practice, crests may be partially or fully rounded. See para. 2.3.1(b).

Internal Thread

External Thread

UN

R m

axim

um

min

or

dia

met

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30 deg

60 deg

0.125P

0.250P

GENERAL NOTE: Lead and angle tolerances are defined in para. 9.

Fig. 2 Disposition of Diametral Tolerances, Allowance, and Crest Clearance for Unified Inch Screw ThreadClasses 1A, 2A, 1B, and 2B

4


UNR contour, see para. 2.3.1(a)

UN (maximum) minor diameter or external

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Basic form

0.041667P

0.125P

For UNR threads, this root is defined as a continuous rounded contour with a radius not less than 0.10825318P. For UN threads this root may be flat. See para. 2.3.1.

1/2 PD tolerance on internal1/2 allowance on (external)

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1/2 tolerance on major diameter of internal

In practice, crests may be partially or fully rounded. See para. 2.3.1(b).

Internal Thread

External Thread

UN

R m

axim

um

min

or

dia

met

er o

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tern

al

60 deg

0.125P

0.250P

30 deg

GENERAL NOTE: Lead and angle tolerances are defined in para. 9.

Fig. 3 Disposition of Diametral Tolerances and Crest Clearances for Unified Inch Screw ThreadClasses 3A and 3B

5




Table 1 Standard Series Threads (UN/UNR)

Threads/in.

Series With GradedPitches

Basic ExtraNominal Size, in. Series With Constant PitchesMajor Course Fine Fine Nominal

Primary Secondary Diameter UNC UNF UNEF 4-UN 6-UN 8-UN 12-UN 16-UN 20-UN 28-UN 32-UN Size, in.

0 . . . 0.0600 . . . 80 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0. . . 1 0.0730 64 72 . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2 . . . 0.0860 56 64 . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. . . 3 0.0990 48 56 . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

4 . . . 0.1120 40 48 . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 . . . 0.1250 40 44 . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 . . . 0.1380 32 40 . . . . . . . . . . . . . . . . . . . . . . . . UNC 68 . . . 0.1640 32 36 . . . . . . . . . . . . . . . . . . . . . . . . UNC 810 . . . 0.1900 24 32 . . . . . . . . . . . . . . . . . . . . . . . . UNF 10

. . . 12 0.2160 24 28 32 . . . . . . . . . . . . . . . . . . UNF UNEF 12

1⁄4 . . . 0.2500 20 28 32 . . . . . . . . . . . . . . . UNC UNF UNEF 1⁄45⁄16 . . . 0.3125 18 24 32 . . . . . . . . . . . . . . . 20 28 UNEF 5⁄163⁄8 . . . 0.3750 16 24 32 . . . . . . . . . . . . UNC 20 28 UNEF 3⁄87⁄16 . . . 0.4375 14 20 28 . . . . . . . . . . . . 16 UNF UNEF 32 7⁄161⁄2 . . . 0.5000 13 20 28 . . . . . . . . . . . . 16 UNF UNEF 32 1⁄29⁄16 . . . 0.5625 12 I8 24 . . . . . . . . . UNC 16 20 28 32 9⁄165⁄8 . . . 0.6250 11 18 24 . . . . . . . . . 12 16 20 28 32 5⁄8

. . . 11⁄16 0.6875 . . . . . . 24 . . . . . . . . . 12 16 20 28 32 11⁄163⁄4 . . . 0.7500 10 16 20 . . . . . . . . . 12 UNF UNEF 28 32 3⁄4

. . . 13⁄16 0.8125 . . . . . . 20 . . . . . . . . . 12 16 UNEF 28 32 13⁄167⁄8 . . . 0.8750 9 14 20 . . . . . . . . . 12 16 UNEF 28 32 7⁄8

. . . 15⁄16 0.9375 . . . . . . 20 . . . . . . . . . 12 16 UNEF 28 32 15⁄16

1 . . . 1.0000 8 12 20 . . . . . . UNC UNF 16 UNEF 28 32 1. . . 11⁄16 1.0625 . . . . . . 18 . . . . . . 8 12 16 20 28 . . . 11⁄16

11⁄8 . . . 1.1250 7 12 18 . . . . . . 8 UNF 16 20 28 . . . 11⁄8. . . 13⁄16 1.1875 . . . . . . 18 . . . . . . 8 12 16 20 28 . . . 13⁄16

11⁄4 . . . 1.2500 7 12 18 . . . . . . 8 UNF 16 20 28 . . . 11⁄4. . . 15⁄16 1.3125 . . . . . . 18 . . . . . . 8 12 16 20 28 . . . 15⁄16

13⁄8 . . . 1.3750 6 12 18 . . . UNC 8 UNF 16 20 28 . . . 13⁄8. . . 17⁄16 1.4375 . . . . . . 18 . . . 6 8 12 16 20 28 . . . 17⁄16

11⁄2 . . . 1.5000 6 12 18 . . . UNC 8 UNF 16 20 28 . .. 11⁄2. . . 19⁄16 1.5625 . . . . . . 18 . . . 6 8 12 16 20 . . . . . . 19⁄16

15⁄8 . . . 1.6250 . . . . . . 18 . . . 6 8 12 16 20 . . . . . . 15⁄8. . . 111⁄16 1.6875 . . . . . . 18 . . . 6 8 12 16 20 . . . . . . 111⁄16

13⁄4 . . . 1.7500 5 . . . . . . . . . 6 8 12 16 20 . . . . . . 13⁄4. . . 113⁄16 1.8125 . . . . . . . . . . . . 6 8 12 16 20 . . . . . . 113⁄16

17⁄8 . . . 1.8750 . . . . . . . . . . . . 6 8 12 16 20 . . . . . . 17⁄8. . . 115⁄16 1.9375 . . . . . . . . . . . . 6 8 12 16 20 . . . . . . 115⁄16

2 . . . 2.0000 41⁄2 . . . . . . . . . 6 8 12 16 20 . . . . . . 2. . . 21⁄8 2.1250 . . . . . . . . . . . . 6 8 12 16 20 . . . . . . 21⁄8

21⁄4 . . . 2.2500 41⁄2 . . . . . . . . . 6 8 12 16 20 . . . . . . 21⁄4. . . 23⁄8 2.3750 . . . . . . . . . . . . 6 8 12 16 20 . . . . . . 23⁄8

21⁄2 . . . 2.5000 4 . . . . . . UNC 6 8 12 16 20 . . . . . . 21⁄2. . . 25⁄8 2.6250 . . . . . . . . . 4 6 8 12 16 20 . . . . . . 25⁄8

23⁄4 . . . 2.7500 4 . . . . . . UNC 6 8 12 16 20 . . . . . . 23⁄4. . . 27⁄8 2.8750 . . . . . . . . . 4 6 8 12 16 20 . . . . . . 27⁄8

6


Table 1 Standard Series Threads (UN/UNR) (Cont’d)

Threads/in.

Series With GradedPitches

Basic ExtraNominal Size, in. Series With Constant PitchesMajor Course Fine Fine Nominal

Primary Secondary Diameter UNC UNF UNEF 4-UN 6-UN 8-UN 12-UN 16-UN 20-UN 28-UN 32-UN Size, in.

3 . . . 3.0000 4 . . . . . . UNC 6 8 12 16 20 . . . . . . 3. . . 31⁄8 3.1250 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 31⁄8

31⁄4 . . . 3.2500 4 . . . . . . UNC 6 8 12 16 . . . . . . . . . 31⁄4. . . 33⁄8 3.3750 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 33⁄8

31⁄2 . . . 3.5000 4 . . . . . . UNC 6 8 12 16 . . . . . . . . . 31⁄2. . . 35⁄8 3.6250 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 35⁄8

33⁄4 . . . 3.7500 4 . . . . . . UNC 6 8 12 16 . . . . . . . . . 33⁄4. . . 37⁄8 3.8750 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 37⁄8

4 . . . 4.0000 4 . . . . . . UNC 6 8 12 1.6 . . . . . . . . . 4. . . 41⁄8 4.1250 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 41⁄8

41⁄4 . . . 4.2500 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 41⁄4. . . 43⁄8 4.3750 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 43⁄8

41⁄2 . . . 4.5000 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 41⁄2. . . 45⁄8 4.6250 . . . . . . . . . 4 6 8 12 16 .. . . . . . . 45⁄8

43⁄4 . . . 4.7500 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 43⁄4. . . 47⁄8 4.8750 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 47⁄8

5 . . . 5.0000 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 5. . . 51⁄8 5.1250 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 51⁄8

51⁄4 . . . 5.2500 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 51⁄4. . . 53⁄8 5.3750 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 53⁄8

51⁄2 . . . 5.5000 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 51⁄2. . . 55⁄8 5.6250 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 55⁄8

53⁄4 . . . 5.7500 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 53⁄4. . . 57⁄8 5.8750 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 57⁄8

6 . . . 6.0000 . . . . . . . . . 4 6 8 12 16 . . . . . . . . . 6

GENERAL NOTE: Series designation shown indicates the UN thread form; however, the UNR thread form may be specifiedby substituting UNR in place of UN in all designations for external use only.

Table 1, offer a comprehensive range of diameter-pitchcombinations for those purposes where the threads inthe coarse-, fine-, and extra-fine-thread series do notmeet the particular requirements of the design. The pri-mary sizes of the 8-UN, 12-UN, and 16-UN series shownin Table 1 are the most commonly used.

Whenever a thread in a constant-pitch series alsoappears in the UNC, UNF, or UNEF series, the symbolsand tolerances for limits of size of those standard seriesare applicable.

3.6.1 8-Thread Series. The 8-thread series (8-UN) isa uniform-pitch series for large diameters or as a com-promise between coarse and fine thread series. Althoughoriginally intended for high-pressure-joint bolts andnuts, it is now widely used as a substitute for the coarsethread series for diameters larger than 1 in.

3.6.2 12-Thread Series. The 12-thread series (12-UN)is a uniform-pitch series for large diameters requiring

7

threads of medium-fine pitch. Although originallyintended for boiler practice, it is now used as a continua-tion of the fine thread series for diameters larger than11⁄2 in.

3.6.3 16-Thread Series. The 16-thread series (16-UN)is a uniform-pitch series for large diameters requiringfine-pitch threads. It is suitable for adjusting collars andretaining nuts and also serves as a continuation of theextra-fine thread series for diameters larger than 111⁄16 in.

3.7 Fine Threads for Thin-Wall Tubing

The limits of size for a 28-thread series, ranging from0.216 in. to 1.5 in. nominal size, are included in Table 2.These threads are recommended for general use on thin-wall tubing. The 27-thread series is no longer standardbut is included in Table D-1 of Nonmandatory Appen-dix D.




Tabl

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and

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met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

0–80

or0.

060–

80U

NF

2A0.

0005

0.05

950.

0563

...

0.05

140.

0496

0.00

1762

0.04

462B

0.04

650.

0514

0.05

190.

0542

0.00

230.

0600

3A0.

0000

0.06

000.

0568

...

0.05

190.

0506

0.00

1300

0.04

513B

0.04

650.

0514

0.05

190.

0536

0.00

170.

0600

(7)

1–64

or0.

073–

64U

NC

2A0.

0006

0.07

240.

0686

...

0.06

230.

0603

0.00

1970

0.05

382B

0.05

610.

0622

0.06

290.

0655

0.00

260.

0730

(7)

3A0.

0000

0.07

300.

0692

...

0.06

290.

0614

0.00

1500

0.05

443B

0.05

610.

0622

0.06

290.

0648

0.00

190.

0730

(7)

1–72

or0.

073–

72U

NF

2A0.

0006

0.07

240.

0689

...

0.06

340.

0615

0.00

1899

0.05

592B

0.05

80.

0634

0.06

400.

0665

0.00

250.

0730

(7)

3A0.

0000

0.07

300.

0695

...

0.06

400.

0626

0.00

1400

0.05

653B

0.05

800.

0634

0.06

400.

0659

0.00

190.

0730

2–56

or0.

086–

56U

NC

2A0.

0006

0.08

540.

0813

...

0.07

380.

0717

0.00

2127

0.06

412B

0.06

670.

0737

0.07

440.

0772

0.00

280.

0860

3A0.

0000

0.08

600.

0819

...

0.07

440.

0728

0.00

1600

0.06

473B

0.06

670.

0737

0.07

440.

0765

0.00

210.

0860

(7)

2–64

or0.

086–

64U

NF

2A0.

0006

0.08

540.

0816

...

0.07

530.

0733

0.00

2040

0.06

682B

0.06

910.

0752

0.07

590.

0786

0.00

270.

0860

(7)

3A0.

0000

0.08

600.

0822

...

0.07

590.

0744

0.00

1500

0.06

743B

0.06

910.

0752

0.07

590.

0779

0.00

200.

0860

3–48

or0.

099–

48U

NC

2A0.

0007

0.09

830.

0938

...

0.08

480.

0825

0.00

2302

0.07

352B

0.07

640.

0845

0.08

550.

0885

0.00

300.

0990

3A0.

0000

0.09

900.

0945

...

0.08

550.

0838

0.00

1700

0.07

423B

0.07

640.

0845

0.08

550.

0877

0.00

220.

0990

3–56

or0.

099–

56U

NF

2A0.

0007

0.09

830.

0942

...

0.08

670.

0845

0.00

2191

0.07

702B

0.07

970.

0865

0.08

740.

0902

0.00

280.

0990

3A0.

0000

0.09

900.

0949

...

0.08

740.

0858

0.00

1600

0.07

773B

0.07

970.

0865

0.08

740.

0895

0.00

210.

0990

4–40

or0.

112–

40U

NC

2A0.

0008

0.11

120.

1061

...

0.09

500.

0925

0.00

2507

0.08

142B

0.08

490.

0939

0.09

580.

0991

0.00

330.

1120

3A0.

0000

0.11

200.

1069

...

0.09

580.

0939

0.00

1900

0.08

223B

0.08

490.

0939

0.09

580.

0982

0.00

240.

1120

4–48

or0.

112–

48U

NF

2A0.

0007

0.11

130.

1068

...

0.09

780.

0954

0.00

2361

0.08

652B

0.08

940.

0968

0.09

850.

1016

0.00

310.

1120

3A0.

0000

0.11

200.

1075

...

0.09

850.

0967

0.00

1800

0.08

723B

0.08

940.

0968

0.09

850.

1008

0.00

230.

1120

5–40

or0.

125–

40U

NC

2A0.

0008

0.12

420.

1191

...

0.10

800.

1054

0.00

2562

0.09

442B

0.09

790.

1062

0.10

880.

1121

0.00

330.

1250

3A0.

0000

0.12

500.

1199

...

0.10

880.

1069

0.00

1900

0.09

523B

0.09

790.

1062

0.10

880.

1113

0.00

250.

1250

5–44

or0.

125–

44U

NF

2A0.

0007

0.12

430.

1195

...

0.10

950.

1070

0.00

2484

0.09

722B

0.10

040.

1079

0.11

020.

1134

0.00

320.

1250

3A0.

0000

0.12

500.

1202

...

0.11

020.

1083

0.00

1900

0.09

793B

0.10

040.

1079

0.11

020.

1126

0.00

240.

1250

6–32

or0.

138–

32U

NC

2A0.

0008

0.13

720.

1312

...

0.11

690.

1141

0.00

2820

0.10

002B

0.10

40.

114

0.11

770.

1214

0.00

370.

1380

(7)

3A0.

0000

0.13

800.

1320

...

0.11

770.

1156

0.00

2100

0.10

083B

0.10

400.

1139

0.11

770.

1204

0.00

270.

1380

6–40

or0.

138–

40U

NF

2A0.

0008

0.13

720.

1321

...

0.12

100.

1184

0.00

2614

0.10

742B

0.11

10.

119

0.12

180.

1252

0.00

340.

1380

3A0.

0000

0.13

800.

1329

...

0.12

180.

1198

0.00

2000

0.10

823B

0.11

100.

1186

0.12

180.

1243

0.00

250.

1380

8


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]M

inor

Func

tion

alD

iam

eter

Ser

ies

Max

.M

ajor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

8–

32or

0.16

4–

32U

NC

2A0.

0009

0.16

310.

1571

...

0.14

280.

1399

0.00

2916

0.12

592B

0.13

00.

139

0.14

370.

1475

0.00

380.

1640

(7)

3A0.

0000

0.16

400.

1580

...

0.14

370.

1415

0.00

2200

0.12

683B

0.13

000.

1388

0.14

370.

1465

0.00

280.

1640

8–

36or

0.16

4–

36U

NF

2A0.

0008

0.16

320.

1577

...

0.14

520.

1424

0.00

2804

0.13

012B

0.13

40.

142

0.14

600.

1496

0.00

360.

1640

3A0.

0000

0.16

400.

1585

...

0.14

600.

1439

0.00

2100

0.13

093B

0.13

400.

1416

0.14

600.

1487

0.00

270.

1640

(7)

10–

24or

0.19

0–

24U

NC

2A0.

0010

0.18

900.

1818

...

0.16

190.

1586

0.00

3319

0.13

942B

0.14

50.

155

0.16

290.

1672

0.00

430.

1900

3A0.

0000

0.19

000.

1828

...

0.16

290.

1604

0.00

2500

0.14

043B

0.14

500.

1555

0.16

290.

1661

0.00

320.

1900

10–

32or

0.19

0–

32U

NF

2A0.

0009

0.18

910.

1831

...

0.16

880.

1658

0.00

3004

0.15

192B

0.15

60.

164

0.16

970.

1736

0.00

390.

1900

3A0.

0000

0.19

000.

1840

...

0.16

970.

1674

0.00

2300

0.15

283B

0.15

600.

1641

0.16

970.

1726

0.00

290.

1900

12–

24or

0.21

6–

24U

NC

2A0.

0010

0.21

500.

2078

...

0.18

790.

1845

0.00

3400

0.16

542B

0.17

10.

181

0.18

890.

1933

0.00

440.

2160

3A0.

0000

0.21

600.

2088

...

0.18

890.

1863

0.00

2600

0.16

643B

0.17

100.

1807

0.18

890.

1922

0.00

330.

2160

12–

28or

0.21

6–

28U

NF

2A0.

0010

0.21

500.

2085

...

0.19

180.

1886

0.00

3224

0.17

252B

0.17

70.

186

0.19

280.

1970

0.00

420.

2160

3A0.

0000

0.21

600.

2095

...

0.19

280.

1904

0.00

2400

0.17

353B

0.17

700.

1857

0.19

280.

1959

0.00

310.

2160

(7)

12–

32or

0.21

6–

32U

NEF

2A0.

0010

0.21

500.

2090

...

0.19

470.

1915

0.00

3184

0.17

782B

0.18

20.

190

0.19

570.

1998

0.00

410.

2160

3A0.

0000

0.21

600.

2100

...

0.19

570.

1933

0.00

2400

0.17

883B

0.18

200.

1895

0.19

570.

1988

0.00

310.

2160

1 ⁄ 4–

20or

0.25

00–

20U

NC

1A0.

0011

0.24

890.

2367

...

0.21

640.

2108

0.00

5600

0.18

941B

0.19

60.

207

0.21

750.

2248

0.00

730.

2500

2A0.

0011

0.24

890.

2408

0.23

670.

2164

0.21

270.

0037

310.

1894

2B0.

196

0.20

70.

2175

0.22

240.

0049

0.25

003A

0.00

000.

2500

0.24

19..

.0.

2175

0.21

470.

0028

000.

1905

3B0.

1960

0.20

670.

2175

0.22

110.

0036

0.25

00

1 ⁄ 4–

28or

0.25

00–

28U

NF

1A0.

0010

0.24

900.

2392

...

0.22

580.

2208

0.00

5000

0.20

651B

0.21

10.

220.

2268

0.23

330.

0065

0.25

002A

0.00

100.

2490

0.24

25..

.0.

2258

0.22

250.

0033

220.

2065

2B0.

211

0.22

00.

2268

0.23

110.

0043

0.25

003A

0.00

000.

2500

0.24

35..

.0.

2268

0.22

430.

0025

000.

2075

3B0.

2110

0.21

900.

2268

0.23

000.

0032

0.25

00

1 ⁄ 4–

32or

0.25

00–

32U

NEF

2A0.

0010

0.24

900.

2430

...

0.22

870.

2255

0.00

3229

0.21

182B

0.21

60.

224

0.22

970.

2339

0.00

420.

2500

3A0.

0000

0.25

000.

2440

...

0.22

970.

2273

0.00

2400

0.21

283B

0.21

600.

2229

0.22

970.

2328

0.00

310.

2500

5 ⁄ 16

–18

or0.

3125

–18

UN

C1A

0.00

120.

3113

0.29

82..

.0.

2752

0.26

910.

0061

000.

2451

1B0.

252

0.26

50.

2764

0.28

430.

0079

0.31

252A

0.00

120.

3113

0.30

260.

2982

0.27

520.

2712

0.00

4041

0.24

512B

0.25

20.

265

0.27

640.

2817

0.00

530.

3125

3A0.

0000

0.31

250.

3038

...

0.27

640.

2734

0.00

3000

0.24

633B

0.25

200.

2630

0.27

640.

2803

0.00

390.

3125

(7)

5 ⁄ 16

–20

or0.

3125

–20

UN

2A0.

0012

0.31

130.

3032

...

0.27

880.

2747

0.00

4060

0.25

182B

0.25

80.

270

0.28

000.

2853

0.00

530.

3125

(7)

3A0.

0000

0.31

250.

3044

...

0.28

000.

2770

0.00

3000

0.25

303B

0.25

800.

2680

0.28

000.

2840

0.00

400.

3125

9




Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]M

inor

Func

tion

alD

iam

eter

Ser

ies

Max

.M

ajor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

5 ⁄ 16

–24

or0.

3125

–24

UN

F1A

0.00

110.

3114

0.30

06..

.0.

2843

0.27

880.

0055

000.

2618

1B0.

267

0.27

70.

2854

0.29

250.

0071

0.31

252A

0.00

110.

3114

0.30

42..

.0.

2843

0.28

060.

0036

600.

2618

2B0.

267

0.27

70.

2854

0.29

020.

0048

0.31

253A

0.00

000.

3125

0.30

53..

.0.

2854

0.28

270.

0027

000.

2629

3B0.

2670

0.27

540.

2854

0.28

900.

0036

0.31

25

(7)

5 ⁄ 16

–28

or0.

3125

–28

UN

2A0.

0010

0.31

150.

3050

...

0.28

830.

2848

0.00

3495

0.26

902B

0.27

40.

282

0.28

930.

2938

0.00

450.

3125

(7)

3A0.

0000

0.31

250.

3060

...

0.28

930.

2867

0.00

2600

0.27

003B

0.27

400.

2807

0.28

930.

2927

0.00

340.

3125

(7)

5 ⁄ 16

–32

or0.

3125

–32

UN

EF2A

0.00

100.

3115

0.30

55..

.0.

2912

0.28

790.

0033

020.

2743

2B0.

279

0.28

60.

2922

0.29

650.

0043

0.31

25(7

)3A

0.00

000.

3125

0.30

65..

.0.

2922

0.28

970.

0025

000.

2753

3B0.

2790

0.28

460.

2922

0.29

540.

0032

0.31

25

3 ⁄ 8–

16or

0.37

50–

16U

NC

1A0.

0013

0.37

370.

3595

...

0.33

310.

3266

0.00

6500

0.29

931B

0.30

70.

321

0.33

440.

3429

0.00

850.

3750

2A0.

0013

0.37

370.

3643

0.35

950.

3331

0.32

870.

0043

630.

2993

2B0.

307

0.32

10.

3344

0.34

010.

0057

0.37

503A

0.00

000.

3750

0.36

56..

.0.

3344

0.33

110.

0033

000.

3006

3B0.

3070

0.31

820.

3344

0.33

870.

0043

0.37

50

3 ⁄ 8–

20or

0.37

50–

20U

N2A

0.00

120.

3738

0.36

57..

.0.

3413

0.33

720.

0041

240.

3143

2B0.

321

0.33

20.

3425

0.34

790.

0054

0.37

503A

0.00

000.

3750

0.36

69..

.0.

3425

0.33

940.

0031

000.

3155

3B0.

3210

0.32

970.

3425

0.34

650.

0040

0.37

50

3 ⁄ 8–

24or

0.37

50–

24U

NF

1A0.

0011

0.37

390.

3631

...

0.34

680.

3411

0.00

5700

0.32

431B

0.33

0.34

0.34

790.

3553

0.00

740.

3750

2A0.

0011

0.37

390.

3667

...

0.34

680.

3430

0.00

3804

0.32

432B

0.33

00.

340

0.34

790.

3528

0.00

490.

3750

3A0.

0000

0.37

500.

3678

...

0.34

790.

3450

0.00

2900

0.32

543B

0.33

000.

3372

0.34

790.

3516

0.00

370.

3750

3 ⁄ 8–

28or

0.37

50–

28U

N2A

0.00

110.

3739

0.36

74..

.0.

3507

0.34

710.

0035

590.

3314

2B0.

336

0.34

50.

3518

0.35

640.

0046

0.37

503A

0.00

000.

3750

0.36

85..

.0.

3518

0.34

910.

0027

000.

3325

3B0.

3360

0.34

260.

3518

0.35

530.

0035

0.37

50

3 ⁄ 8–

32or

0.37

50–

32U

NEF

2A0.

0010

0.37

400.

3680

...

0.35

370.

3503

0.00

3366

0.33

682B

0.34

10.

349

0.35

470.

3591

0.00

440.

3750

3A0.

0000

0.37

500.

3690

...

0.35

470.

3522

0.00

2500

0.33

783B

0.34

100.

3469

0.35

470.

3580

0.00

330.

3750

7 ⁄ 16

–14

or0.

4375

–14

UN

C1A

0.00

140.

4361

0.42

06..

.0.

3897

0.38

260.

0071

000.

3510

1B0.

360.

376

0.39

110.

4003

0.00

920.

4375

2A0.

0014

0.43

610.

4258

0.42

060.

3897

0.38

500.

0047

130.

3510

2B0.

360

0.37

60.

3911

0.39

720.

0061

0.43

753A

0.00

000.

4375

0.42

72..

.0.

3911

0.38

760.

0035

000.

3524

3B0.

3600

0.37

170.

3911

0.39

570.

0046

0.43

75

(7)

7 ⁄ 16

–16

or0.

4375

–16

UN

2A0.

0014

0.43

610.

4267

...

0.39

550.

3909

0.00

4626

0.36

172B

0.37

00.

384

0.39

690.

4029

0.00

600.

4375

(7)

3A0.

0000

0.43

750.

4281

...

0.39

690.

3934

0.00

3500

0.36

313B

0.37

000.

3800

0.39

690.

4014

0.00

450.

4375

(7)

7 ⁄ 16

–20

or0.

4375

–20

UN

F1A

0.00

130.

4362

0.42

40..

.0.

4037

0.39

740.

0063

000.

3767

1B0.

383

0.39

50.

4050

0.41

310.

0081

0.43

752A

0.00

130.

4362

0.42

81..

.0.

4037

0.39

950.

0041

670.

3767

2B0.

383

0.39

50.

4050

0.41

040.

0054

0.43

753A

0.00

000.

4375

0.42

94..

.0.

4050

0.40

190.

0031

000.

3780

3B0.

3830

0.39

160.

4050

0.40

910.

0041

0.43

75

10


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UN

RM

inor

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

Func

tion

alD

iam

eter

[Not

e(4

)]M

inor

Func

tion

alD

iam

eter

Ser

ies

Max

.M

ajor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(7)

7 ⁄ 16

–28

or0.

4375

–28

UN

EF2A

0.00

110.

4364

0.42

99..

.0.

4132

0.40

960.

0036

160.

3939

2B0.

399

0.40

70.

4143

0.41

900.

0047

0.43

753A

0.00

000.

4375

0.43

10..

.0.

4143

0.41

160.

0027

000.

3950

3B0.

3990

0.40

510.

4143

0.41

780.

0035

0.43

75

(7)

7 ⁄ 16

–32

or0.

4375

–32

UN

2A0.

0010

0.43

650.

4305

...

0.41

620.

4128

0.00

3423

0.39

932B

0.40

40.

411

0.41

720.

4216

0.00

440.

4375

3A0.

0000

0.43

750.

4315

...

0.41

720.

4146

0.00

2600

0.40

033B

0.40

400.

4094

0.41

720.

4205

0.00

330.

4375

1 ⁄ 2–

13or

0.50

00–

13U

NC

1A0.

0015

0.49

850.

4822

...

0.44

850.

4411

0.00

7400

0.40

691B

0.41

70.

434

0.45

000.

4597

0.00

970.

5000

2A0.

0015

0.49

850.

4876

0.48

220.

4485

0.44

350.

0049

650.

4069

2B0.

417

0.43

40.

4500

0.45

650.

0065

0.50

003A

0.00

000.

5000

0.48

91..

.0.

4500

0.44

630.

0037

000.

4084

3B0.

4170

0.42

840.

4500

0.45

480.

0048

0.50

00

1 ⁄ 2–

16or

0.50

00–

16U

N2A

0.00

140.

4986

0.48

92..

.0.

4580

0.45

330.

0046

780.

4242

2B0.

432

0.44

60.

4594

0.46

550.

0061

0.50

00(7

)3A

0.00

000.

5000

0.49

06..

.0.

4594

0.45

590.

0035

000.

4256

3B0.

4320

0.44

200.

4594

0.46

400.

0046

0.50

00

1 ⁄ 2–

20or

0.50

00–

20U

NF

1A0.

0013

0.49

870.

4865

...

0.46

620.

4598

0.00

6400

0.43

921B

0.44

60.

457

0.46

750.

4759

0.00

840.

5000

2A0.

0013

0.49

870.

4906

...

0.46

620.

4619

0.00

4288

0.43

922B

0.44

60.

457

0.46

750.

4731

0.00

560.

5000

3A0.

0000

0.50

000.

4919

...

0.46

750.

4643

0.00

3200

0.44

053B

0.44

600.

4537

0.46

750.

4717

0.00

420.

5000

1 ⁄ 2–

28or

0.50

00–

28U

NEF

2A0.

0011

0.49

890.

4924

...

0.47

570.

4720

0.00

3668

0.45

642B

0.46

10.

470

0.47

680.

4816

0.00

480.

5000

3A0.

0000

0.50

000.

4935

...

0.47

680.

4740

0.00

2800

0.45

753B

0.46

100.

4676

0.47

680.

4804

0.00

360.

5000

1 ⁄ 2–

32or

0.50

00–

32U

N2A

0.00

100.

4990

0.49

30..

.0.

4787

0.47

520.

0034

750.

4618

2B0.

466

0.47

40.

4797

0.48

420.

0045

0.50

003A

0.00

000.

5000

0.49

40..

.0.

4797

0.47

710.

0026

000.

4628

3B0.

4660

0.47

190.

4797

0.48

310.

0034

0.50

00

9 ⁄ 16

–12

or0.

5625

–12

UN

C1A

0.00

160.

5609

0.54

37..

.0.

5068

0.49

900.

0078

000.

4617

1B0.

472

0.49

0.50

840.

5186

0.01

020.

5625

2A0.

0016

0.56

090.

5495

0.54

370.

5068

0.50

160.

0052

250.

4617

2B0.

472

0.49

00.

5084

0.51

520.

0068

0.56

253A

0.00

000.

5625

0.55

11..

.0.

5084

0.50

450.

0039

000.

4633

3B0.

4720

0.48

430.

5084

0.51

350.

0051

0.56

25

9 ⁄ 16

–16

or0.

5625

–16

UN

2A0.

0014

0.56

110.

5517

...

0.52

050.

5158

0.00

4725

0.48

672B

0.49

50.

509

0.52

190.

5280

0.00

610.

5625

(7)

3A0.

0000

0.56

250.

5531

...

0.52

190.

5184

0.00

3500

0.48

813B

0.49

500.

5041

0.52

190.

5265

0.00

460.

5625

9 ⁄ 16

–18

or0.

5625

–18

UN

F1A

0.00

140.

5611

0.54

80..

.0.

5250

0.51

820.

0068

000.

4949

1B0.

502

0.51

50.

5264

0.53

530.

0089

0.56

252A

0.00

140.

5611

0.55

24..

.0.

5250

0.52

050.

0045

470.

4949

2B0.

502

0.51

50.

5264

0.53

230.

0059

0.56

253A

0.00

000.

5625

0.55

38..

.0.

5264

0.52

300.

0034

000.

4963

3B0.

5020

0.51

060.

5264

0.53

080.

0044

0.56

25

(7)

9 ⁄ 16

–20

or0.

5625

–20

UN

2A0.

0013

0.56

120.

5531

...

0.52

870.

5244

0.00

4280

0.50

172B

0.50

80.

520

0.53

000.

5356

0.00

560.

5625

(7)

3A0.

0000

0.56

250.

5544

...

0.53

000.

5268

0.00

3200

0.50

303B

0.50

800.

5161

0.53

000.

5342

0.00

420.

5625

(7)

9 ⁄ 16

–24

or0.

5625

–24

UN

EF2A

0.00

120.

5613

0.55

41..

.0.

5342

0.53

020.

0039

600.

5117

2B0.

517

0.52

70.

5354

0.54

050.

0051

0.56

25(7

)3A

0.00

000.

5625

0.55

53..

.0.

5354

0.53

240.

0030

000.

5129

3B0.

5170

0.52

440.

5354

0.53

930.

0039

0.56

25

11




Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]M

inor

Func

tion

alD

iam

eter

Ser

ies

Max

.M

ajor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

9 ⁄ 16

–28

or0.

5625

–28

UN

2A0.

0011

0.56

140.

5549

...

0.53

820.

5345

0.00

3715

0.51

892B

0.52

40.

532

0.53

930.

5441

0.00

480.

5625

3A0.

0000

0.56

250.

5560

...

0.53

930.

5365

0.00

2800

0.52

003B

0.52

400.

5301

0.53

930.

5429

0.00

360.

5625

(7)

9 ⁄ 16

–32

or0.

5625

–32

UN

2A0.

0011

0.56

140.

5554

...

0.54

110.

5376

0.00

3522

0.52

422B

0.52

90.

536

0.54

220.

5468

0.00

460.

5625

3A0.

0000

0.56

250.

5565

...

0.54

220.

5396

0.00

2600

0.52

533B

0.52

900.

5344

0.54

220.

5456

0.00

340.

5625

(7)

5 ⁄ 8–

11or

0.62

50–

11U

NC

1A0.

0017

0.62

330.

6051

...

0.56

430.

5560

0.00

8300

0.51

501B

0.52

70.

546

0.56

600.

5767

0.01

070.

6250

(7)

2A0.

0017

0.62

330.

6112

0.60

520.

5643

0.55

880.

0055

010.

5150

2B0.

527

0.54

60.

5660

0.57

320.

0072

0.62

503A

0.00

000.

6250

0.61

29..

.0.

5660

0.56

190.

0041

000.

5167

3B0.

5270

0.53

910.

5660

0.57

140.

0054

0.62

50

5 ⁄ 8–

12or

0.62

50–

12U

N2A

0.00

160.

6234

0.61

20..

.0.

5693

0.56

390.

0054

430.

5242

2B0.

535

0.55

30.

5709

0.57

800.

0071

0.62

503A

0.00

000.

6250

0.61

36..

.0.

5709

0.56

680.

0041

000.

5258

3B0.

5350

0.54

630.

5709

0.57

620.

0053

0.62

50

5 ⁄ 8–

16or

0.62

50–

16U

N2A

0.00

140.

6236

0.61

42..

.0.

5830

0.57

820.

0047

690.

5492

2B0.

557

0.57

10.

5844

0.59

060.

0062

0.62

503A

0.00

000.

6250

0.61

56..

.0.

5844

0.58

080.

0036

000.

5506

3B0.

5570

0.56

620.

5844

0.58

900.

0046

0.62

50

5 ⁄ 8–

18or

0.62

50–

18U

NF

1A0.

0014

0.62

360.

6105

...

0.58

750.

5805

0.00

7000

0.55

741B

0.56

50.

578

0.58

890.

5980

0.00

910.

6250

2A0.

0014

0.62

360.

6149

...

0.58

750.

5828

0.00

4652

0.55

742B

0.56

50.

578

0.58

890.

5949

0.00

600.

6250

3A0.

0000

0.62

500.

6163

...

0.58

890.

5854

0.00

3500

0.55

883B

0.56

500.

5730

0.58

890.

5934

0.00

450.

6250

5 ⁄ 8–

20or

0.62

50–

20U

N2A

0.00

130.

6237

0.61

56..

.0.

5912

0.58

690.

0043

240.

5642

2B0.

571

0.58

20.

5925

0.59

810.

0056

0.62

503A

0.00

000.

6250

0.61

69..

.0.

5925

0.58

930.

0032

000.

5655

3B0.

5710

0.57

860.

5925

0.59

670.

0042

0.62

50

5 ⁄ 8–

24or

0.62

50–

24U

NEF

2A0.

0012

0.62

380.

6166

...

0.59

670.

5927

0.00

4004

0.57

422B

0.58

00.

590

0.59

790.

6031

0.00

520.

6250

3A0.

0000

0.62

500.

6178

...

0.59

790.

5949

0.00

3000

0.57

543B

0.58

000.

5869

0.59

790.

6018

0.00

390.

6250

5 ⁄ 8–

28or

0.62

50–

28U

N2A

0.00

110.

6239

0.61

74..

.0.

6007

0.59

690.

0037

590.

5814

2B0.

586

0.59

50.

6018

0.60

670.

0049

0.62

503A

0.00

000.

6250

0.61

85..

.0.

6018

0.59

900.

0028

000.

5825

3B0.

5860

0.59

260.

6018

0.60

550.

0037

0.62

50

(7)

5 ⁄ 8–

32or

0.62

50–

32U

N2A

0.00

110.

6239

0.61

79..

.0.

6036

0.60

000.

0035

660.

5867

2B0.

591

0.59

90.

6047

0.60

930.

0046

0.62

503A

0.00

000.

6250

0.61

90..

.0.

6047

0.60

200.

0027

000.

5878

3B0.

5910

0.59

690.

6047

0.60

820.

0035

0.62

50

(7)

11⁄ 1

6–12

or0.

6875

–12

UN

2A0.

0016

0.68

590.

6745

...

0.63

180.

6263

0.00

5485

0.58

672B

0.59

70.

615

0.63

340.

6405

0.00

710.

6875

3A0.

0000

0.68

750.

6761

...

0.63

340.

6293

0.00

4100

0.58

833B

0.59

700.

6085

0.63

340.

6387

0.00

530.

6875

(7)

11⁄ 1

6–16

or0.

6875

–16

UN

2A0.

0014

0.68

610.

6767

...

0.64

550.

6407

0.00

4811

0.61

172B

0.62

00.

634

0.64

690.

6532

0.00

630.

6875

3A0.

0000

0.68

750.

6781

...

0.64

690.

6433

0.00

3600

0.61

313B

0.62

000.

6284

0.64

690.

6516

0.00

470.

6875

12


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]M

inor

Func

tion

alD

iam

eter

Ser

ies

Max

.M

ajor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(7)

11⁄ 1

6–20

or0.

6875

–20

UN

2A0.

0013

0.68

620.

6781

...

0.65

370.

6493

0.00

4366

0.62

672B

0.63

30.

645

0.65

500.

6607

0.00

570.

6875

(7)

3A0.

0000

0.68

750.

6794

...

0.65

500.

6517

0.00

3300

0.62

803B

0.63

300.

6411

0.65

500.

6593

0.00

430.

6875

(7)

11⁄ 1

6–24

or0.

6875

–24

UN

EF2A

0.00

120.

6863

0.67

91..

.0.

6592

0.65

520.

0040

460.

6367

2B0.

642

0.65

20.

6604

0.66

570.

0053

0.68

753A

0.00

000.

6875

0.68

03..

.0.

6604

0.65

740.

0030

000.

6379

3B0.

6420

0.64

940.

6604

0.66

430.

0039

0.68

75

11⁄ 1

6–28

or0.

6875

–28

UN

2A0.

0011

0.68

640.

6799

...

0.66

320.

6594

0.00

3801

0.64

392B

0.64

90.

657

0.66

430.

6692

0.00

490.

6875

(7)

3A0.

0000

0.68

750.

6810

...

0.66

430.

6614

0.00

2900

0.64

503B

0.64

900.

6551

0.66

430.

6680

0.00

370.

6875

(7)

11⁄ 1

6–32

or0.

6875

–32

UN

2A0.

0011

0.68

640.

6804

...

0.66

610.

6625

0.00

3608

0.64

922B

0.65

40.

661

0.66

720.

6719

0.00

470.

6875

3A0.

0000

0.68

750.

6815

...

0.66

720.

6645

0.00

2700

0.65

033B

0.65

400.

6594

0.66

720.

6707

0.00

350.

6875

3 ⁄ 4–

10or

0.75

00–

10U

NC

1A0.

0018

0.74

820.

7288

...

0.68

320.

6744

0.00

8800

0.62

911B

0.64

20.

663

0.68

500.

6965

0.01

150.

7500

2A0.

0018

0.74

820.

7353

0.72

880.

6832

0.67

730.

0058

940.

6291

2B0.

642

0.66

30.

6850

0.69

270.

0077

0.75

003A

0.00

000.

7500

0.73

71..

.0.

6850

0.68

060.

0044

000.

6309

3B0.

6420

0.65

450.

6850

0.69

070.

0057

0.75

00

3 ⁄ 4–

12or

0.75

00–

12U

N2A

0.00

170.

7483

0.73

69..

.0.

6942

0.68

870.

0055

240.

6491

2B0.

660

0.67

80.

6959

0.70

310.

0072

0.75

003A

0.00

000.

7500

0.73

86..

.0.

6959

0.69

180.

0041

000.

6508

3B0.

6600

0.67

070.

6959

0.70

130.

0054

0.75

00

3 ⁄ 4–

16or

0.75

00–

16U

NF

1A0.

0015

0.74

850.

7343

...

0.70

790.

7004

0.00

7500

0.67

411B

0.68

20.

696

0.70

940.

7192

0.00

980.

7500

2A0.

0015

0.74

850.

7391

...

0.70

790.

7029

0.00

5024

0.67

412B

0.68

20.

696

0.70

940.

7159

0.00

650.

7500

(7)

3A0.

0000

0.75

000.

7406

...

0.70

940.

7056

0.00

3800

0.67

563B

0.68

200.

6909

0.70

940.

7143

0.00

490.

7500

3 ⁄ 4–

20or

0.75

00–

20U

NEF

2A0.

0013

0.74

870.

7406

...

0.71

620.

7118

0.00

4405

0.68

922B

0.69

60.

707

0.71

750.

7232

0.00

570.

7500

(7)

3A0.

0000

0.75

000.

7419

...

0.71

750.

7142

0.00

3300

0.69

053B

0.69

600.

7036

0.71

750.

7218

0.00

430.

7500

3 ⁄ 4–

28or

0.75

00–

28U

N2A

0.00

120.

7488

0.74

23..

.0.

7256

0.72

180.

0038

400.

7063

2B0.

711

0.72

00.

7268

0.73

180.

0050

0.75

00(7

)3A

0.00

000.

7500

0.74

35..

.0.

7268

0.72

390.

0029

000.

7075

3B0.

7110

0.71

760.

7268

0.73

050.

0037

0.75

00

3 ⁄ 4–

32or

0.75

00–

32U

N2A

0.00

110.

7489

0.74

29..

.0.

7286

0.72

500.

0036

470.

7117

2B0.

716

0.72

40.

7297

0.73

440.

0047

0.75

003A

0.00

000.

7500

0.74

40..

.0.

7297

0.72

700.

0027

000.

7128

3B0.

7160

0.72

190.

7297

0.73

330.

0036

0.75

00

(7)

13⁄ 1

6–12

or0.

8125

–12

UN

2A0.

0017

0.81

080.

7994

...

0.75

670.

7511

0.00

5561

0.71

162B

0.72

20.

740

0.75

840.

7656

0.00

720.

8125

(7)

3A0.

0000

0.81

250.

8011

...

0.75

840.

7542

0.00

4200

0.71

333B

0.72

200.

7329

0.75

840.

7638

0.00

540.

8125

(7)

13⁄ 1

6–16

or0.

8125

–16

UN

2A0.

0015

0.81

100.

8016

...

0.77

040.

7655

0.00

4887

0.73

662B

0.74

50.

759

0.77

190.

7783

0.00

640.

8125

(7)

3A0.

0000

0.81

250.

8031

...

0.77

190.

7682

0.00

3700

0.73

813B

0.74

500.

7534

0.77

190.

7767

0.00

480.

8125

13




Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(7)

13⁄ 1

6–20

or0.

8125

–20

UN

EF2A

0.00

130.

8112

0.80

31..

.0.

7787

0.77

430.

0044

420.

7517

2B0.

758

0.77

00.

7800

0.78

580.

0058

0.81

25(7

)3A

0.00

000.

8125

0.80

44..

.0.

7800

0.77

670.

0033

000.

7530

3B0.

7580

0.76

610.

7800

0.78

430.

0043

0.81

25

(7)

13⁄ 1

6–28

or0.

8125

–28

UN

2A0.

0012

0.81

130.

8048

...

0.78

810.

7842

0.00

3877

0.76

882B

0.77

40.

782

0.78

930.

7943

0.00

500.

8125

(7)

3A0.

0000

0.81

250.

8060

...

0.78

930.

7864

0.00

2900

0.77

003B

0.77

400.

7801

0.78

930.

7931

0.00

380.

8125

(7)

13⁄ 1

6–32

or0.

8125

–32

UN

2A0.

0011

0.81

140.

8054

...

0.79

110.

7874

0.00

3684

0.77

422B

0.77

90.

786

0.79

220.

7970

0.00

480.

8125

(7)

3A0.

0000

0.81

250.

8065

...

0.79

220.

7894

0.00

2800

0.77

533B

0.77

900.

7844

0.79

220.

7958

0.00

360.

8125

7 ⁄ 8–

9or

0.87

50–

9U

NC

1A0.

0019

0.87

310.

8523

...

0.80

090.

7914

0.00

9500

0.74

081B

0.75

50.

778

0.80

280.

8151

0.01

230.

8750

2A0.

0019

0.87

310.

8592

0.85

230.

8009

0.79

460.

0063

050.

7408

2B0.

755

0.77

80.

8028

0.81

100.

0082

0.87

503A

0.00

000.

8750

0.86

11..

.0.

8028

0.79

810.

0047

000.

7427

3B0.

7550

0.76

810.

8028

0.80

890.

0061

0.87

50

(7)

7 ⁄ 8–

12or

0.87

50–

12U

N2A

0.00

170.

8733

0.86

19..

.0.

8192

0.81

360.

0055

960.

7741

2B0.

785

0.80

30.

8209

0.82

820.

0073

0.87

50(7

)3A

0.00

000.

8750

0.86

36..

.0.

8209

0.81

670.

0042

000.

7758

3B0.

7850

0.79

520.

8209

0.82

640.

0055

0.87

50

(7)

7 ⁄ 8–

14or

0.87

50–

14U

NF

1A0.

0016

0.87

340.

8579

...

0.82

700.

8189

0.00

8100

0.78

831B

0.79

80.

813

0.82

860.

8392

0.01

060.

8750

(7)

2A0.

0016

0.87

340.

8631

...

0.82

700.

8216

0.00

5420

0.78

832B

0.79

80.

813

0.82

860.

8356

0.00

700.

8750

(7)

3A0.

0000

0.87

500.

8647

...

0.82

860.

8245

0.00

4100

0.78

993B

0.79

800.

8067

0.82

860.

8339

0.00

530.

8750

(7)

7 ⁄ 8–

16or

0.87

50–

16U

N2A

0.00

150.

8735

0.86

41..

.0.

8329

0.82

800.

0049

220.

7991

2B0.

807

0.82

10.

8344

0.84

080.

0064

0.87

50(7

)3A

0.00

000.

8750

0.86

56..

.0.

8344

0.83

070.

0037

000.

8006

3B0.

8070

0.81

590.

8344

0.83

920.

0048

0.87

50

(7)

7 ⁄ 8–

20or

0.87

50–

20U

NEF

2A0.

0013

0.87

370.

8656

...

0.84

120.

8367

0.00

4477

0.81

422B

0.82

10.

832

0.84

250.

8483

0.00

580.

8750

(7)

3A7

0.00

000.

8750

0.86

69..

.0.

8425

0.83

910.

0034

000.

8155

3B0.

8210

0.82

860.

8425

0.84

690.

0044

0.87

50

(7)

7 ⁄ 8–

28or

0.87

50–

28U

N2A

0.00

120.

8738

0.86

73..

.0.

8506

0.84

670.

0039

120.

8313

2B0.

836

0.84

50.

8518

0.85

690.

0051

0.87

50(7

)3A

70.

0000

0.87

500.

8685

...

0.85

180.

8489

0.00

2900

0.83

253B

0.83

600.

8426

0.85

180.

8556

0.00

380.

8750

(7)

7 ⁄ 8–

32or

0.87

50–

32U

N2A

0.00

110.

8739

0.86

79..

.0.

8536

0.84

990.

0037

190.

8367

2B0.

841

0.84

90.

8547

0.85

950.

0048

0.87

50(7

)3A

0.00

000.

8750

0.86

90..

.0.

8547

0.85

190.

0028

000.

8378

3B0.

8410

0.84

690.

8547

0.85

830.

0036

0.87

50

(7)

15⁄ 1

6–12

or0.

9375

–12

UN

2A0.

0017

0.93

580.

9244

...

0.88

170.

8761

0.00

5629

0.83

662B

0.84

70.

865

0.88

340.

8907

0.00

730.

9375

(7)

3A7

0.00

000.

9375

0.92

61..

.0.

8834

0.87

920.

0042

000.

8383

3B0.

8470

0.85

750.

8834

0.88

890.

0055

0.93

75

(7)

15⁄ 1

6–16

or0.

9375

–16

UN

2A0.

0015

0.93

600.

9266

...

0.89

540.

8904

0.00

4955

0.86

162B

0.87

00.

884

0.89

690.

9033

0.00

640.

9375

(7)

3A0.

0000

0.93

750.

9281

...

0.89

690.

8932

0.00

3700

0.86

313B

0.87

000.

8784

0.89

690.

9017

0.00

480.

9375

14


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

15⁄ 1

6–

20or

0.93

75–

20U

NEF

2A0.

0014

0.93

610.

9280

...

0.90

360.

8991

0.00

4510

0.87

662B

0.88

30.

895

0.90

500.

9109

0.00

590.

9375

(7)

3A0.

0000

0.93

750.

9294

...

0.90

500.

9016

0.00

3400

0.87

803B

0.88

300.

8911

0.90

500.

9094

0.00

440.

9375

(7)

15⁄ 1

6–28

or0.

9375

–28

UN

2A0.

0012

0.93

630.

9298

...

0.91

310.

9092

0.00

3945

0.89

382B

0.89

90.

907

0.91

430.

9194

0.00

510.

9375

(7)

3A0.

0000

0.93

750.

9310

...

0.91

430.

9113

0.00

3000

0.89

503B

0.89

900.

9051

0.91

430.

9181

0.00

380.

9375

15⁄ 1

6–

32or

0.93

75–

32U

N2A

0.00

110.

9364

0.93

04..

.0.

9161

0.91

230.

0037

520.

8992

2B0.

904

0.91

10.

9172

0.92

210.

0049

0.93

753A

0.00

000.

9375

0.93

15..

.0.

9172

0.91

440.

0028

000.

9003

3B0.

9040

0.90

940.

9172

0.92

090.

0037

0.93

75

(7)

1–

8or

1.00

00–

8U

NC

1A0.

0020

0.99

800.

9755

...

0.91

680.

9067

0.01

0100

0.84

921B

0.86

50.

890.

9188

0.93

200.

0132

1.00

002A

0.00

200.

9980

0.98

300.

9755

0.91

680.

9101

0.00

6750

0.84

922B

0.86

50.

890

0.91

880.

9276

0.00

881.

0000

3A0.

0000

1.00

000.

9850

...

0.91

880.

9137

0.00

5100

0.85

123B

0.86

500.

8797

0.91

880.

9254

0.00

661.

0000

1–

12or

1.00

00–

12U

NF

1A0.

0018

0.99

820.

9810

...

0.94

410.

9353

0.00

8800

0.89

901B

0.91

0.92

80.

9459

0.95

730.

0114

1.00

002A

0.00

180.

9982

0.98

68..

.0.

9441

0.93

820.

0058

620.

8990

2B0.

910

0.92

80.

9459

0.95

350.

0076

1.00

003A

0.00

001.

0000

0.98

86..

.0.

9459

0.94

150.

0044

000.

9008

3B0.

9100

0.91

980.

9459

0.95

160.

0057

1.00

00

(7)

1–

14or

1.00

00–

14U

NS

(8)

2A0.

0016

0.99

840.

9881

...

0.95

200.

9467

0.00

5285

0.91

332B

0.92

30.

938

0.95

360.

9605

0.00

691.

0000

(7)

3A0.

0000

1.00

000.

9897

...

0.95

360.

9496

0.00

4000

0.91

493B

0.92

300.

9315

0.95

360.

9588

0.00

521.

0000

1–

16or

1.00

00–

16U

N2A

0.00

150.

9985

0.98

91..

.0.

9579

0.95

290.

0049

870.

9241

2B0.

932

0.94

60.

9594

0.96

590.

0065

1.00

003A

0.00

001.

0000

0.99

06..

.0.

9594

0.95

570.

0037

000.

9256

3B0.

9320

0.94

090.

9594

0.96

430.

0049

1.00

00

1–

20or

1.00

00–

20U

NEF

2A0.

0014

0.99

860.

9905

...

0.96

610.

9616

0.00

4542

0.93

912B

0.94

60.

957

0.96

750.

9734

0.00

591.

0000

3A0.

0000

1.00

000.

9919

...

0.96

750.

9641

0.00

3400

0.94

053B

0.94

600.

9536

0.96

750.

9719

0.00

441.

0000

1–

28or

1.00

00–

28U

N2A

0.00

120.

9988

0.99

23..

.0.

9756

0.97

160.

0039

770.

9563

2B0.

961

0.97

00.

9768

0.98

200.

0052

1.00

003A

0.00

001.

0000

0.99

35..

.0.

9768

0.97

380.

0030

000.

9575

3B0.

9610

0.96

760.

9768

0.98

070.

0039

1.00

00

1–

32or

1.00

00–

32U

N2A

0.00

110.

9989

0.99

29..

.0.

9786

0.97

480.

0037

840.

9617

2B0.

966

0.97

40.

9797

0.98

460.

0049

1.00

003A

0.00

001.

0000

0.99

40..

.0.

9797

0.97

690.

0028

000.

9628

3B0.

9660

0.97

190.

9797

0.98

340.

0037

1.00

00

11 ⁄ 16

–8

or1.

0625

–8

UN

2A0.

0020

1.06

051.

0455

...

0.97

930.

9725

0.00

6827

0.91

172B

0.92

70.

952

0.98

130.

9902

0.00

891.

0625

3A0.

0000

1.06

251.

0475

...

0.98

130.

9762

0.00

5100

0.91

373B

0.92

700.

9422

0.98

130.

9880

0.00

671.

0625

11 ⁄ 16

–12

or1.

0625

–12

UN

2A0.

0017

1.06

081.

0494

...

1.00

671.

0010

0.00

5692

0.96

162B

0.97

20.

990

1.00

841.

0158

0.00

741.

0625

(7)

3A0.

0000

1.06

251.

0511

...

1.00

841.

0041

0.00

4300

0.96

333B

0.97

200.

9823

1.00

841.

0139

0.00

551.

0625

11 ⁄ 16

–16

or1.

0625

–16

UN

2A0.

0015

1.06

101.

0516

...

1.02

041.

0154

0.00

5018

0.98

662B

0.99

51.

009

1.02

191.

0284

0.00

651.

0625

(7)

3A0.

0000

1.06

251.

0531

...

1.02

191.

0181

0.00

3800

0.98

813B

0.99

501.

0034

1.02

191.

0268

0.00

491.

0625

15




Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alPi

tch

Dia

met

eran

dD

iam

eter

,M

ajor

Dia

met

erD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(7)

11 ⁄ 16

–18

or1.

0625

–18

UN

EF2A

0.00

141.

0611

1.05

24..

.1.

0250

1.02

020.

0047

760.

9949

2B1.

002

1.01

51.

0264

1.03

260.

0062

1.06

25(7

)3A

0.00

001.

0625

1.05

38..

.1.

0264

1.02

280.

0036

000.

9963

3B1.

0020

1.01

051.

0264

1.03

110.

0047

1.06

25

(7)

11 ⁄ 16

–20

or1.

0625

–20

UN

2A0.

0014

1.06

111.

0530

...

1.02

861.

0240

0.00

4573

1.00

162B

1.00

81.

020

1.03

001.

0359

0.00

591.

0625

(7)

3A0.

0000

1.06

251.

0544

...

1.03

001.

0266

0.00

3400

1.00

303B

1.00

801.

0161

1.03

001.

0345

0.00

451.

0625

11 ⁄ 16

–28

or1.

0625

–28

UN

2A0.

0012

1.06

131.

0548

...

1.03

811.

0341

0.00

4008

1.01

882B

1.02

41.

032

1.03

931.

0445

0.00

521.

0625

3A0.

0000

1.06

251.

0560

...

1.03

931.

0363

0.00

3000

1.02

003B

1.02

401.

0301

1.03

931.

0432

0.00

391.

0625

11 ⁄ 8–

7or

1.12

50–

7U

NC

1A0.

0022

1.12

281.

0982

...

1.03

001.

0191

0.01

0900

0.95

271B

0.97

0.99

81.

0322

1.04

630.

0141

1.12

50(7

)2A

0.00

221.

1228

1.10

641.

0982

1.03

001.

0228

0.00

7250

0.95

272B

0.97

00.

998

1.03

221.

0416

0.00

941.

1250

3A0.

0000

1.12

501.

1086

...

1.03

221.

0268

0.00

5400

0.95

493B

0.97

000.

9875

1.03

221.

0393

0.00

711.

1250

11 ⁄ 8–

8or

1.12

50–

8U

N2A

0.00

211.

1229

1.10

791.

1004

1.04

171.

0348

0.00

6901

0.97

412B

0.99

01.

015

1.04

381.

0528

0.00

901.

1250

3A0.

0000

1.12

501.

1100

...

1.04

381.

0386

0.00

5200

0.97

623B

0.99

001.

0047

1.04

381.

0505

0.00

671.

1250

11 ⁄ 8–

12or

1.12

50–

12U

NF

1A0.

0018

1.12

321.

1060

...

1.06

911.

0601

0.00

9000

1.02

401B

1.03

51.

053

1.07

091.

0826

0.01

171.

1250

2A0.

0018

1.12

321.

1118

...

1.06

911.

0631

0.00

6013

1.02

402B

1.03

51.

053

1.07

091.

0787

0.00

781.

1250

3A0.

0000

1.12

501.

1136

...

1.07

091.

0664

0.00

4500

1.02

583B

1.03

501.

0448

1.07

091.

0768

0.00

591.

1250

(7)

11 ⁄ 8–

16or

1.12

50–

16U

N2A

0.00

151.

1235

1.11

41..

.1.

0829

1.07

790.

0050

471.

0491

2B1.

057

1.07

11.

0844

1.09

100.

0066

1.12

50(7

)3A

0.00

001.

1250

1.11

56..

.1.

0844

1.08

060.

0038

001.

0506

3B1.

0570

1.06

591.

0844

1.08

930.

0049

1.12

50

(7)

11 ⁄ 8–

18or

1.12

50–

18U

NEF

2A0.

0014

1.12

361.

1149

...

1.08

751.

0827

0.00

4805

1.05

742B

1.06

51.

078

1.08

891.

0951

0.00

621.

1250

(7)

3A0.

0000

1.12

501.

1163

...

1.08

891.

0853

0.00

3600

1.05

883B

1.06

501.

0730

1.08

891.

0936

0.00

471.

1250

(7)

11 ⁄ 8–

20or

1.12

50–

20U

N2A

0.00

141.

1236

1.11

55..

.1.

0911

1.08

650.

0046

021.

0641

2B1.

071

1.08

21.

0925

1.09

850.

0060

1.12

50(7

)3A

0.00

001.

1250

1.11

69..

.1.

0925

1.08

900.

0035

001.

0655

3B1.

0710

1.07

861.

0925

1.09

700.

0045

1.12

50

11 ⁄ 8–

28or

1.12

50–

28U

N2A

0.00

121.

1238

1.11

73..

.1.

1006

1.09

660.

0040

371.

0813

2B1.

086

1.09

51.

1018

1.10

700.

0052

1.12

503A

0.00

001.

1250

1.11

85..

.1.

1018

1.09

880.

0030

001.

0825

3B1.

0860

1.09

261.

1018

1.10

570.

0039

1.12

50

13 ⁄ 16

–8

or1.

1875

–8

UN

2A0.

0021

1.18

541.

1704

...

1.10

421.

0972

0.00

6973

1.03

662B

1.05

21.

077

1.10

631.

1154

0.00

911.

1875

3A0.

0000

1.18

751.

1725

...

1.10

631.

1011

0.00

5200

1.03

873B

1.05

201.

0672

1.10

631.

1131

0.00

681.

1875

(7)

13 ⁄ 16

–12

or1.

1875

–12

UN

2A0.

0017

1.18

581.

1744

...

1.13

171.

1260

0.00

5749

1.08

662B

1.09

71.

115

1.13

341.

1409

0.00

751.

1875

3A0.

0000

1.18

751.

1761

...

1.13

341.

1291

0.00

4300

1.08

833B

1.09

701.

1073

1.13

341.

1390

0.00

561.

1875

16


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alPi

tch

Dia

met

eran

dD

iam

eter

,M

ajor

Dia

met

erD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

13 ⁄ 16

–16

or1.

1875

–16

UN

2A0.

0015

1.18

601.

1766

...

1.14

541.

1403

0.00

5075

1.11

162B

1.12

01.

134

1.14

691.

1535

0.00

661.

1875

(7)

3A0.

0000

1.18

751.

1781

...

1.14

691.

1431

0.00

3800

1.11

313B

1.12

001.

1284

1.14

691.

1518

0.00

491.

1875

(7)

13 ⁄ 16

–18

or1.

1875

–18

UN

EF2A

0.00

141.

1861

1.17

74..

.1.

1500

1.14

520.

0048

331.

1199

2B1.

127

1.14

01.

1514

1.15

770.

0063

1.18

753A

0.00

001.

1875

1.17

88..

.1.

1514

1.14

780.

0036

001.

1213

3B1.

1270

1.13

551.

1514

1.15

610.

0047

1.18

75

(7)

13 ⁄ 16

–20

or1.

1875

–20

UN

2A0.

0014

1.18

611.

1780

...

1.15

361.

1490

0.00

4630

1.12

662B

1.13

31.

145

1.15

501.

1610

0.00

601.

1875

(7)

3A0.

0000

1.18

751.

1794

...

1.15

501.

1515

0.00

3500

1.12

803B

1.13

301.

1411

1.15

501.

1595

0.00

451.

1875

13 ⁄ 16

–28

or1.

1875

–28

UN

2A0.

0012

1.18

631.

1798

...

1.16

311.

1590

0.00

4065

1.14

382B

1.14

91.

157

1.16

431.

1696

0.00

531.

1875

3A0.

0000

1.18

751.

1810

...

1.16

431.

1613

0.00

3000

1.14

503B

1.14

901.

1551

1.16

431.

1683

0.00

401.

1875

11 ⁄ 4–

7or

1.25

00–

7U

NC

1A0.

0022

1.24

781.

2232

...

1.15

501.

1439

0.01

1100

1.07

771B

1.09

51.

123

1.15

721.

1716

0.01

441.

2500

2A0.

0022

1.24

781.

2314

1.22

321.

1550

1.14

760.

0073

921.

0777

2B1.

095

1.12

31.

1572

1.16

680.

0096

1.25

003A

0.00

001.

2500

1.23

36..

.1.

1572

1.15

170.

0055

001.

0799

3B1.

0950

1.11

251.

1572

1.16

440.

0072

1.25

00

11 ⁄ 4–

8or

1.25

00–

8U

N2A

0.00

211.

2479

1.23

291.

2254

1.16

671.

1597

0.00

7043

1.09

912B

1.11

51.

140

1.16

881.

1780

0.00

921.

2500

3A0.

0000

1.25

001.

2350

...

1.16

881.

1635

0.00

5300

1.10

123B

1.11

501.

1297

1.16

881.

1757

0.00

691.

2500

11 ⁄ 4–

12or

1.25

00–

12U

NF

1A0.

0018

1.24

821.

2310

...

1.19

411.

1849

0.00

9200

1.14

901B

1.16

1.17

81.

1959

1.20

790.

0120

1.25

002A

0.00

181.

2482

1.23

68..

.1.

1941

1.18

790.

0061

551.

1490

2B1.

160

1.17

81.

1959

1.20

390.

0080

1.25

003A

0.00

001.

2500

1.23

86..

.1.

1959

1.19

130.

0046

001.

1508

3B1.

1600

1.16

981.

1959

1.20

190.

0060

1.25

00

11 ⁄ 4–

16or

1.25

00–

16U

N2A

0.00

151.

2485

1.23

91..

.1.

2079

1.20

280.

0051

031.

1741

2B1.

182

1.19

61.

2094

1.21

600.

0066

1.25

00(7

)3A

0.00

001.

2500

1.24

06..

.1.

2094

1.20

560.

0038

001.

1756

3B1.

1820

1.19

091.

2094

1.21

440.

0050

1.25

00

11 ⁄ 4–

18or

1.25

00–

18U

NEF

2A0.

0015

1.24

851.

2398

...

1.21

241.

2075

0.00

4861

1.18

232B

1.19

01.

203

1.21

391.

2202

0.00

631.

2500

3A0.

0000

1.25

001.

2413

...

1.21

391.

2103

0.00

3600

1.18

383B

1.19

001.

1980

1.21

391.

2186

0.00

471.

2500

11 ⁄ 4–

20or

1.25

00–

20U

N2A

0.00

141.

2486

1.24

05..

.1.

2161

1.21

140.

0046

581.

1891

2B1.

196

1.20

71.

2175

1.22

360.

0061

1.25

00(7

)3A

0.00

001.

2500

1.24

19..

.1.

2175

1.21

400.

0035

001.

1905

3B1.

1960

1.20

361.

2175

1.22

200.

0045

1.25

00

11 ⁄ 4–

28or

1.25

00–

28U

N2A

0.00

121.

2488

1.24

23..

.1.

2256

1.22

150.

0040

931.

2063

2B1.

211

1.22

01.

2268

1.23

210.

0053

1.25

003A

0.00

001.

2500

1.24

35..

.1.

2268

1.22

370.

0031

001.

2075

3B1.

2110

1.21

761.

2268

1.23

080.

0040

1.25

00

15 ⁄ 16

–8

or1.

3125

–8

UN

2A0.

0021

1.31

041.

2954

...

1.22

921.

2221

0.00

7110

1.16

162B

1.17

71.

202

1.23

131.

2405

0.00

921.

3125

3A0.

0000

1.31

251.

2975

...

1.23

131.

2260

0.00

5300

1.16

373B

1.17

701.

1922

1.23

131.

2382

0.00

691.

3125

17




Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

15 ⁄ 16

–12

or1.

3125

–12

UN

2A0.

0017

1.31

081.

2994

...

1.25

671.

2509

0.00

5803

1.21

162B

1.22

21.

240

1.25

841.

2659

0.00

751.

3125

(7)

3A0.

0000

1.31

251.

3011

...

1.25

841.

2540

0.00

4400

1.21

333B

1.22

201.

2323

1.25

841.

2641

0.00

571.

3125

(7)

15 ⁄ 16

–16

or1.

3125

–16

UN

2A0.

0015

1.31

101.

3016

...

1.27

041.

2653

0.00

5129

1.23

662B

1.24

51.

259

1.27

191.

2786

0.00

671.

3125

(7)

3A0.

0000

1.31

251.

3031

...

1.27

191.

2681

0.00

3800

1.23

813B

1.24

501.

2534

1.27

191.

2769

0.00

501.

3125

(7)

15 ⁄ 16

–18

or1.

3125

–18

UN

EF2A

0.00

151.

3110

1.30

23..

.1.

2749

1.27

000.

0048

871.

2448

2B1.

252

1.26

51.

2764

1.28

280.

0064

1.31

25(7

)3A

0.00

001.

3125

1.30

38..

.1.

2764

1.27

270.

0037

001.

2463

3B1.

2520

1.26

051.

2764

1.28

120.

0048

1.31

25

15 ⁄ 16

–20

or1.

3125

–20

UN

2A0.

0014

1.31

111.

3030

...

1.27

861.

2739

0.00

4684

1.25

162B

1.25

81.

270

1.28

001.

2861

0.00

611.

3125

(7)

3A0.

0000

1.31

251.

3044

...

1.28

001.

2765

0.00

3500

1.25

303B

1.25

801.

2661

1.28

001.

2846

0.00

461.

3125

(7)

15 ⁄ 16

–28

or1.

3125

–28

UN

2A0.

0012

1.31

131.

3048

...

1.28

811.

2840

0.00

4119

1.26

882B

1.27

41.

282

1.28

931.

2947

0.00

541.

3125

3A0.

0000

1.31

251.

3060

...

1.28

931.

2862

0.00

3100

1.27

003B

1.27

401.

2801

1.28

931.

2933

0.00

401.

3125

13 ⁄ 8–

6or

1.37

50–

6U

NC

1A0.

0024

1.37

261.

3453

...

1.26

431.

2523

0.01

2000

1.17

411B

1.19

51.

225

1.26

671.

2822

0.01

551.

3750

2A0.

0024

1.37

261.

3544

1.34

531.

2643

1.25

630.

0079

701.

1741

2B1.

195

1.22

51.

2667

1.27

710.

0104

1.37

503A

0.00

001.

3750

1.35

68..

.1.

2667

1.26

070.

0060

001.

1765

3B1.

1950

1.21

461.

2667

1.27

450.

0078

1.37

50

13 ⁄ 8–

8or

1.37

50–

8U

N2A

0.00

221.

3728

1.35

781.

3503

1.29

161.

2844

0.00

7177

1.22

402B

1.24

01.

265

1.29

381.

3031

0.00

931.

3750

3A0.

0000

1.37

501.

3600

...

1.29

381.

2884

0.00

5400

1.22

623B

1.24

001.

2547

1.29

381.

3008

0.00

701.

3750

13 ⁄ 8–

12or

1.37

50–

12U

NF

1A0.

0019

1.37

311.

3559

...

1.31

901.

3096

0.00

9400

1.27

391B

1.28

51.

303

1.32

091.

3332

0.01

231.

3750

2A0.

0019

1.37

311.

3617

...

1.31

901.

3127

0.00

6289

1.27

392B

1.28

51.

303

1.32

091.

3291

0.00

821.

3750

3A0.

0000

1.37

501.

3636

...

1.32

091.

3162

0.00

4700

1.27

583B

1.28

501.

2948

1.32

091.

3270

0.00

611.

3750

(7)

13 ⁄ 8–

16or

1.37

50–

16U

N2A

0.00

151.

3735

1.36

41..

.1.

3329

1.32

770.

0051

551.

2991

2B1.

307

1.32

11.

3344

1.34

110.

0067

1.37

50(7

)3A

0.00

001.

3750

1.36

56..

.1.

3344

1.33

050.

0039

001.

3006

3B1.

3070

1.31

591.

3344

1.33

940.

0050

1.37

50

(7)

13 ⁄ 8–

18or

1.37

50–

18U

NEF

2A0.

0015

1.37

351.

3648

...

1.33

741.

3325

0.00

4913

1.30

732B

1.31

51.

328

1.33

891.

3453

0.00

641.

3750

(7)

3A0.

0000

1.37

501.

3663

...

1.33

891.

3352

0.00

3700

1.30

883B

1.31

501.

3230

1.33

891.

3437

0.00

481.

3750

13 ⁄ 8–

20or

1.37

50–

20U

N2A

0.00

141.

3736

1.36

55..

.1.

3411

1.33

640.

0047

101.

3141

2B1.

321

1.33

21.

3425

1.34

860.

0061

1.37

50(7

)3A

0.00

001.

3750

1.36

69..

.1.

3425

1.33

900.

0035

001.

3155

3B1.

3210

1.32

861.

3425

1.34

710.

0046

1.37

50

(7)

13 ⁄ 8–

28or

1.37

50–

28U

N2A

0.00

121.

3738

1.36

73..

.1.

3506

1.34

650.

0041

451.

3313

2B1.

336

1.34

51.

3518

1.35

720.

0054

1.37

503A

0.00

001.

3750

1.36

85..

.1.

3518

1.34

870.

0031

001.

3325

3B1.

3360

1.34

261.

3518

1.35

580.

0040

1.37

50

18


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alPi

tch

Dia

met

eran

dD

iam

eter

,M

ajor

Dia

met

erD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

17 ⁄ 16

–6

or1.

4375

–6

UN

2A0.

0024

1.43

511.

4169

...

1.32

681.

3188

0.00

8034

1.23

662B

1.25

71.

288

1.32

921.

3396

0.01

041.

4375

3A0.

0000

1.43

751.

4193

...

1.32

921.

3232

0.00

6000

1.23

903B

1.25

701.

2771

1.32

921.

3370

0.00

781.

4375

17 ⁄ 16

–8

or1.

4375

–8

UN

2A0.

0022

1.43

531.

4203

...

1.35

411.

3469

0.00

7241

1.28

652B

1.30

21.

327

1.35

631.

3657

0.00

941.

4375

3A0.

0000

1.43

751.

4225

...

1.35

631.

3509

0.00

5400

1.28

873B

1.30

201.

3172

1.35

631.

3634

0.00

711.

4375

17 ⁄ 16

–12

or1.

4375

–12

UN

2A0.

0018

1.43

571.

4243

...

1.38

161.

3757

0.00

5854

1.33

652B

1.34

71.

365

1.38

341.

3910

0.00

761.

4375

3A0.

0000

1.43

751.

4261

...

1.38

341.

3790

0.00

4400

1.33

833B

1.34

701.

3573

1.38

341.

3891

0.00

571.

4375

(7)

17 ⁄ 16

–16

or1.

4375

–16

UN

2A0.

0016

1.43

591.

4265

...

1.39

531.

3901

0.00

5180

1.36

152B

1.37

01.

384

1.39

691.

4036

0.00

671.

4375

(7)

3A0.

0000

1.43

751.

4281

...

1.39

691.

3930

0.00

3900

1.36

313B

1.37

001.

3784

1.39

691.

4020

0.00

511.

4375

(7)

17 ⁄ 16

–18

or1.

4375

–18

UN

EF2A

0.00

151.

4360

1.42

73..

.1.

3999

1.39

500.

0049

381.

3698

2B1.

377

1.39

01.

4014

1.40

780.

0064

1.43

753A

0.00

001.

4375

1.42

88..

.1.

4014

1.39

770.

0037

001.

3713

3B1.

3770

1.38

551.

4014

1.40

620.

0048

1.43

75

(7)

17 ⁄ 16

–20

or1.

4375

–20

UN

2A0.

0014

1.43

611.

4280

...

1.40

361.

3989

0.00

4735

1.37

662B

1.38

31.

395

1.40

501.

4112

0.00

621.

4375

(7)

3A0.

0000

1.43

751.

4294

...

1.40

501.

4014

0.00

3600

1.37

803B

1.38

301.

3911

1.40

501.

4096

0.00

461.

4375

(7)

17 ⁄ 16

–28

or1.

4375

–28

UN

2A0.

0013

1.43

621.

4297

...

1.41

301.

4088

0.00

4170

1.39

372B

1.39

91.

407

1.41

431.

4197

0.00

541.

4375

3A0.

0000

1.43

751.

4310

...

1.41

431.

4112

0.00

3100

1.39

503B

1.39

901.

4051

1.41

431.

4184

0.00

411.

4375

11 ⁄ 2–

6or

1.50

00–

6U

NC

1A0.

0024

1.49

761.

4703

...

1.38

931.

3772

0.01

2100

1.29

911B

1.32

1.35

1.39

171.

4075

0.01

581.

5000

2A0.

0024

1.49

761.

4794

1.47

031.

3893

1.38

120.

0080

971.

2991

2B1.

320

1.35

01.

3917

1.40

220.

0105

1.50

003A

0.00

001.

5000

1.48

18..

.1.

3917

1.38

560.

0061

001.

3015

3B1.

3200

1.33

961.

3917

1.39

960.

0079

1.50

00

11 ⁄ 2–

8or

1.50

00–

8U

N2A

0.00

221.

4978

1.48

281.

4753

1.41

661.

4093

0.00

7304

1.34

902B

1.36

51.

390

1.41

881.

4283

0.00

951.

5000

3A0.

0000

1.50

001.

4850

...

1.41

881.

4133

0.00

5500

1.35

123B

1.36

501.

3797

1.41

881.

4259

0.00

711.

5000

11 ⁄ 2–

12or

1.50

00–

12U

NF

1A0.

0019

1.49

811.

4809

...

1.44

401.

4344

0.00

9600

1.39

891B

1.41

1.42

81.

4459

1.45

840.

0125

1.50

002A

0.00

191.

4981

1.48

67..

.1.

4440

1.43

760.

0064

161.

3989

2B1.

410

1.42

81.

4459

1.45

420.

0083

1.50

003A

0.00

001.

5000

1.48

86..

.1.

4459

1.44

110.

0048

001.

4008

3B1.

4100

1.41

981.

4459

1.45

220.

0063

1.50

00

(7)

11 ⁄ 2–

16or

1.50

00–

16U

N2A

0.00

161.

4984

1.48

90..

.1.

4578

1.45

260.

0052

041.

4240

2B1.

432

1.44

61.

4594

1.46

620.

0068

1.50

003A

0.00

001.

5000

1.49

06..

.1.

4594

1.45

550.

0039

001.

4256

3B1.

4320

1.44

091.

4594

1.46

450.

0051

1.50

00

(7)

11 ⁄ 2–

18or

1.50

00–

18U

NEF

2A0.

0015

1.49

851.

4898

...

1.46

241.

4574

0.00

4962

1.43

232B

1.44

01.

453

1.46

391.

4704

0.00

651.

5000

3A0.

0000

1.50

001.

4913

...

1.46

391.

4602

0.00

3700

1.43

383B

1.44

001.

4480

1.46

391.

4687

0.00

481.

5000

19




Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

11 ⁄ 2–

20or

1.50

00–

20U

N2A

0.00

141.

4986

1.49

05..

.1.

4661

1.46

130.

0047

591.

4391

2B1.

446

1.45

71.

4675

1.47

370.

0062

1.50

00(7

)3A

0.00

001.

5000

1.49

19..

.1.

4675

1.46

390.

0036

001.

4405

3B1.

4460

1.45

361.

4675

1.47

210.

0046

1.50

00

11 ⁄ 2–

28or

1.50

00–

28U

N2A

0.00

131.

4987

1.49

22..

.1.

4755

1.47

130.

0041

941.

4562

2B1.

461

1.47

01.

4768

1.48

230.

0055

1.50

003A

0.00

001.

5000

1.49

35..

.1.

4768

1.47

370.

0031

001.

4575

3B1.

4610

1.46

761.

4768

1.48

090.

0041

1.50

00

19 ⁄ 16

–6

or1.

5625

–6

UN

2A0.

0024

1.56

011.

5419

...

1.45

181.

4436

0.00

8159

1.36

162B

1.38

21.

413

1.45

421.

4648

0.01

061.

5625

3A0.

0000

1.56

251.

5443

...

1.45

421.

4481

0.00

6100

1.36

403B

1.38

201.

4021

1.45

421.

4622

0.00

801.

5625

19 ⁄ 16

–8

or1.

5625

–8

UN

2A0.

0022

1.56

031.

5453

...

1.47

911.

4717

0.00

7366

1.41

152B

1.42

71.

452

1.48

131.

4909

0.00

961.

5625

3A0.

0000

1.56

251.

5475

...

1.48

131.

4758

0.00

5500

1.41

373B

1.42

701.

4422

1.48

131.

4885

0.00

721.

5625

(7)

19 ⁄ 16

–12

or1.

5625

–12

UN

2A0.

0018

1.56

071.

5493

...

1.50

661.

5007

0.00

5902

1.46

152B

1.47

21.

490

1.50

841.

5161

0.00

771.

5625

(7)

3A0.

0000

1.56

251.

5511

...

1.50

841.

5040

0.00

4400

1.46

333B

1.47

201.

4823

1.50

841.

5142

0.00

581.

5625

19 ⁄ 16

–16

or1.

5625

–16

UN

2A0.

0016

1.56

091.

5515

...

1.52

031.

5151

0.00

5228

1.48

652B

1.49

51.

509

1.52

191.

5287

0.00

681.

5625

(7)

3A0.

0000

1.56

251.

5531

...

1.52

191.

5180

0.00

3900

1.48

813B

1.49

501.

5034

1.52

191.

5270

0.00

511.

5625

19 ⁄ 16

–18

or1.

5625

–18

UN

EF2A

0.00

151.

5610

1.55

23..

.1.

5249

1.51

990.

0049

861.

4948

2B1.

502

1.51

51.

5264

1.53

290.

0065

1.56

25(7

)3A

0.00

001.

5625

1.55

38..

.1.

5264

1.52

270.

0037

001.

4963

3B1.

5020

1.51

051.

5264

1.53

130.

0049

1.56

25

19 ⁄ 16

–20

or1.

5625

–20

UN

2A0.

0014

1.56

111.

5530

...

1.52

861.

5238

0.00

4783

1.50

162B

1.50

81.

520

1.53

001.

5362

0.00

621.

5625

(7)

3A0.

0000

1.56

251.

5544

...

1.53

001.

5264

0.00

3600

1.50

303B

1.50

801.

5161

1.53

001.

5347

0.00

471.

5625

15 ⁄ 8–

6or

1.62

50–

6U

N2A

0.00

251.

6225

1.60

43..

.1.

5142

1.50

600.

0082

191.

4240

2B1.

445

1.47

51.

5167

1.52

740.

0107

1.62

503A

0.00

001.

6250

1.60

68..

.1.

5167

1.51

050.

0062

001.

4265

3B1.

4450

1.46

461.

5167

1.52

470.

0080

1.62

50

15 ⁄ 8–

8or

1.62

50–

8U

N2A

0.00

221.

6228

1.60

781.

6003

1.54

161.

5342

0.00

7426

1.47

402B

1.49

01.

515

1.54

381.

5535

0.00

971.

6250

3A0.

0000

1.62

501.

6100

...

1.54

381.

5382

0.00

5600

1.47

623B

1.49

001.

5047

1.54

381.

5510

0.00

721.

6250

(7)

15 ⁄ 8–

12or

1.62

50–

12U

N2A

0.00

181.

6232

1.61

18..

.1.

5691

1.56

320.

0059

251.

5240

2B1.

535

1.55

31.

5709

1.57

860.

0077

1.62

50(7

)3A

0.00

001.

6250

1.61

36..

.1.

5709

1.56

650.

0044

001.

5258

3B1.

5350

1.54

481.

5709

1.57

670.

0058

1.62

50

(7)

15 ⁄ 8–

16or

1.62

50–

16U

N2A

0.00

161.

6234

1.61

40..

.1.

5828

1.57

750.

0052

511.

5490

2B1.

557

1.57

11.

5844

1.59

120.

0068

1.62

503A

0.00

001.

6250

1.61

56..

.1.

5844

1.58

050.

0039

001.

5506

3B1.

5570

1.56

591.

5844

1.58

950.

0051

1.62

50

(7)

15 ⁄ 8–

18or

1.62

50–

18U

NEF

2A0.

0015

1.62

351.

6148

...

1.58

741.

5824

0.00

5009

1.55

732B

1.56

51.

578

1.58

891.

5954

0.00

651.

6250

3A0.

0000

1.62

501.

6163

...

1.58

891.

5851

0.00

3800

1.55

883B

1.56

501.

5730

1.58

891.

5938

0.00

491.

6250

20


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(7)

15 ⁄ 8–

20or

1.62

50–

20U

N2A

0.00

141.

6236

1.61

55..

.1.

5911

1.58

630.

0048

061.

5641

2B1.

571

1.58

21.

5925

1.59

870.

0062

1.62

503A

0.00

001.

6250

1.61

69..

.1.

5925

1.58

890.

0036

001.

5655

3B1.

5710

1.57

861.

5925

1.59

720.

0047

1.62

50

111⁄ 1

6–

6or

1.68

75–

6U

N2A

0.00

251.

6850

1.66

68..

.1.

5767

1.56

840.

0082

781.

4865

2B1.

507

1.53

81.

5792

1.59

000.

0108

1.68

753A

0.00

001.

6875

1.66

93..

.1.

5792

1.57

300.

0062

001.

4890

3B1.

5070

1.52

711.

5792

1.58

730.

0081

1.68

75

111⁄ 1

6–

8or

1.68

75–

8U

N2A

0.00

221.

6853

1.67

03..

.1.

6041

1.59

660.

0074

851.

5365

2B1.

552

1.57

71.

6063

1.61

600.

0097

1.68

753A

0.00

001.

6875

1.67

25..

.1.

6063

1.60

070.

0056

001.

5387

3B1.

5520

1.56

721.

6063

1.61

360.

0073

1.68

75

(7)

111⁄ 1

6–

12or

1.68

75–

12U

N2A

0.00

181.

6857

1.67

43..

.1.

6316

1.62

570.

0059

471.

5865

2B1.

597

1.61

51.

6334

1.64

110.

0077

1.68

753A

0.00

001.

6875

1.67

61..

.1.

6334

1.62

890.

0045

001.

5883

3B1.

5970

1.60

731.

6334

1.63

920.

0058

1.68

75

111⁄ 1

6–

16or

1.68

75–

16U

N2A

0.00

161.

6859

1.67

65..

.1.

6453

1.64

000.

0052

731.

6115

2B1.

620

1.63

41.

6469

1.65

380.

0069

1.68

75(7

)3A

0.00

001.

6875

1.67

81..

.1.

6469

1.64

290.

0040

001.

6131

3B1.

6200

1.62

841.

6469

1.65

200.

0051

1.68

75

(7)

111⁄ 1

6–

18or

1.68

75–

18U

NEF

2A0.

0015

1.68

601.

6773

...

1.64

991.

6449

0.00

5031

1.61

982B

1.62

71.

640

1.65

141.

6579

0.00

651.

6875

3A0.

0000

1.68

751.

6788

...

1.65

141.

6476

0.00

3800

1.62

133B

1.62

701.

6355

1.65

141.

6563

0.00

491.

6875

(7)

111⁄ 1

6–

20or

1.68

75–

20U

N2A

0.00

141.

6861

1.67

80..

.1.

6536

1.64

880.

0048

281.

6266

2B1.

633

1.64

51.

6550

1.66

130.

0063

1.68

75(7

)3A

0.00

001.

6875

1.67

94..

.1.

6550

1.65

140.

0036

001.

6280

3B1.

6330

1.64

111.

6550

1.65

970.

0047

1.68

75

(7)

13 ⁄ 4–

5or

1.75

00–

5U

NC

1A0.

0027

1.74

731.

7165

...

1.61

741.

6040

0.01

3400

1.50

911B

1.53

31.

567

1.62

011.

6375

0.01

741.

7500

(7)

2A0.

0027

1.74

731.

7268

1.71

651.

6174

1.60

850.

0089

221.

5091

2B1.

533

1.56

71.

6201

1.63

170.

0116

1.75

00(7

)3A

0.00

001.

7500

1.72

95..

.1.

6201

1.61

340.

0067

001.

5118

3B1.

5330

1.55

751.

6201

1.62

880.

0087

1.75

00

13 ⁄ 4–

6or

1.75

00–

6U

N2A

0.00

251.

7475

1.72

93..

.1.

6392

1.63

090.

0083

351.

5490

2B1.

570

1.60

01.

6417

1.65

250.

0108

1.75

003A

0.00

001.

7500

1.73

18..

.1.

6417

1.63

540.

0063

001.

5515

3B1.

5700

1.58

961.

6417

1.64

980.

0081

1.75

00

13 ⁄ 4–

8or

1.75

00–

8U

N2A

0.00

231.

7477

1.73

271.

7252

1.66

651.

6590

0.00

7542

1.59

892B

1.61

51.

640

1.66

881.

6786

0.00

981.

7500

(7)

3A0.

0000

1.75

001.

7350

...

1.66

881.

6631

0.00

5700

1.60

123B

1.61

501.

6297

1.66

881.

6762

0.00

741.

7500

13 ⁄ 4–

12or

1.75

00–

12U

N2A

0.00

181.

7482

1.73

68..

.1.

6941

1.68

810.

0059

691.

6490

2B1.

660

1.67

81.

6959

1.70

370.

0078

1.75

003A

0.00

001.

7500

1.73

86..

.1.

6959

1.69

140.

0045

001.

6508

3B1.

6600

1.66

981.

6959

1.70

170.

0058

1.75

00

13 ⁄ 4–

16or

1.75

00–

16U

N2A

0.00

161.

7484

1.73

90..

.1.

7078

1.70

250.

0052

951.

6740

2B1.

682

1.69

61.

7094

1.71

630.

0069

1.75

00(7

)3A

0.00

001.

7500

1.74

06..

.1.

7094

1.70

540.

0040

001.

6756

3B1.

6820

1.69

091.

7094

1.71

460.

0052

1.75

00

13 ⁄ 4–

20or

1.75

00–

20U

N2A

0.00

151.

7485

1.74

04..

.1.

7160

1.71

120.

0048

501.

6890

2B1.

696

1.70

71.

7175

1.72

380.

0063

1.75

00(7

)3A

0.00

001.

7500

1.74

19..

.1.

7175

1.71

390.

0036

001.

6905

3B1.

6960

1.70

361.

7175

1.72

220.

0047

1.75

00

21




Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e4)

]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

113⁄ 1

6–

6or

1.81

25–

6U

N2A

0.00

251.

8100

1.79

18..

.1.

7017

1.69

330.

0083

911.

6115

2B1.

632

1.66

31.

7042

1.71

510.

0109

1.81

253A

0.00

001.

8125

1.79

43..

.1.

7042

1.69

790.

0063

001.

6140

3B1.

6320

1.65

211.

7042

1.71

240.

0082

1.81

25

113⁄ 1

6–

8or

1.81

25–

8U

N2A

0.00

231.

8102

1.79

52..

.1.

7290

1.72

140.

0075

981.

6614

2B1.

677

1.70

21.

7313

1.74

120.

0099

1.81

253A

0.00

001.

8125

1.79

75..

.1.

7313

1.72

560.

0057

001.

6637

3B1.

6770

1.69

221.

7313

1.73

870.

0074

1.81

25

113⁄ 1

6–

12or

1.81

25–

12U

N2A

0.00

181.

8107

1.79

93..

.1.

7566

1.75

060.

0059

901.

7115

2B1.

722

1.74

01.

7584

1.76

620.

0078

1.81

253A

0.00

001.

8125

1.80

11..

.1.

7584

1.75

390.

0045

001.

7133

3B1.

7220

1.73

231.

7584

1.76

420.

0058

1.81

25

113⁄ 1

6–

16or

1.81

25–

16U

N2A

0.00

161.

8109

1.80

15..

.1.

7703

1.76

500.

0053

161.

7365

2B1.

745

1.75

91.

7719

1.77

880.

0069

1.81

25(7

)3A

0.00

001.

8125

1.80

31..

.1.

7719

1.76

790.

0040

001.

7381

3B1.

7450

1.75

341.

7719

1.77

710.

0052

1.81

25

113⁄ 1

6–

20or

1.81

25–

20U

N2A

0.00

151.

8110

1.80

29..

.1.

7785

1.77

360.

0048

711.

7515

2B1.

758

1.77

01.

7800

1.78

630.

0063

1.81

25(7

)3A

0.00

001.

8125

1.80

44..

.1.

7800

1.77

630.

0037

001.

7530

3B1.

7580

1.76

611.

7800

1.78

470.

0047

1.81

25

17 ⁄ 8–

6or

1.87

50–

6U

N2A

0.00

251.

8725

1.85

43..

.1.

7642

1.75

580.

0084

471.

6740

2B1.

695

1.72

51.

7667

1.77

770.

0110

1.87

503A

0.00

001.

8750

1.85

68..

.1.

7667

1.76

040.

0063

001.

6765

3B1.

6950

1.71

461.

7667

1.77

490.

0082

1.87

50

17 ⁄ 8–

8or

1.87

50–

8U

N2A

0.00

231.

8727

1.85

771.

8502

1.79

151.

7838

0.00

7654

1.72

392B

1.74

01.

765

1.79

381.

8038

0.01

001.

8750

3A0.

0000

1.87

501.

8600

...

1.79

381.

7881

0.00

5700

1.72

623B

1.74

001.

7547

1.79

381.

8013

0.00

751.

8750

17 ⁄ 8–

12or

1.87

50–

12U

N2A

0.00

181.

8732

1.86

18..

.1.

8191

1.81

310.

0060

111.

7740

2B1.

785

1.80

31.

8209

1.82

870.

0078

1.87

50(7

)3A

0.00

001.

8750

1.86

36..

.1.

8209

1.81

640.

0045

001.

7758

3B1.

7850

1.79

481.

8209

1.82

680.

0059

1.87

50

17 ⁄ 8

–16

or1.

8750

–16

UN

2A0.

0016

1.87

341.

8640

...

1.83

281.

8275

0.00

5337

1.79

902B

1.80

71.

821

1.83

441.

8413

0.00

691.

8750

(7)

3A0.

0000

1.87

501.

8656

...

1.83

441.

8304

0.00

4000

1.80

063B

1.80

701.

8159

1.83

441.

8396

0.00

521.

8750

(7)

17 ⁄ 8–

20or

1.87

50–

20U

N2A

0.00

151.

8735

1.86

54..

.1.

8410

1.83

610.

0048

921.

8140

2B1.

821

1.83

21.

8425

1.84

890.

0064

1.87

50(7

)3A

0.00

001.

8750

1.86

69..

.1.

8425

1.83

880.

0037

001.

8155

3B1.

8210

1.82

861.

8425

1.84

730.

0048

1.87

50

115⁄ 1

6–

6or

1.93

75–

6U

N2A

0.00

261.

9349

1.91

67..

.1.

8266

1.81

810.

0085

011.

7364

2B1.

757

1.78

81.

8292

1.84

030.

0111

1.93

753A

0.00

001.

9375

1.91

93..

.1.

8292

1.82

280.

0064

001.

7390

3B1.

7570

1.77

711.

8292

1.83

750.

0083

1.93

75

115⁄ 1

6–

8or

1.93

75–

8U

N2A

0.00

231.

9352

1.92

02..

.1.

8540

1.84

630.

0077

081.

7864

2B1.

802

1.82

71.

8563

1.86

630.

0100

1.93

753A

0.00

001.

9375

1.92

25..

.1.

8563

1.85

050.

0058

001.

7887

3B1.

8020

1.81

721.

8563

1.86

380.

0075

1.93

75

(7)

115⁄ 1

6–

12or

1.93

75–

12U

N2A

0.00

181.

9357

1.92

43..

.1.

8816

1.87

560.

0060

311.

8365

2B1.

847

1.86

51.

8834

1.89

120.

0078

1.93

753A

0.00

001.

9375

1.92

61..

.1.

8834

1.87

890.

0045

001.

8383

3B1.

8470

1.85

731.

8834

1.88

930.

0059

1.93

75

22


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

115⁄ 1

6–

16or

1.93

75–

16U

N2A

0.00

161.

9359

1.92

65..

.1.

8953

1.88

990.

0053

571.

8615

2B1.

870

1.88

41.

8969

1.90

390.

0070

1.93

75(7

)3A

0.00

001.

9375

1.92

81..

.1.

8969

1.89

290.

0040

001.

8631

3B1.

8700

1.87

841.

8969

1.90

210.

0052

1.93

75

115⁄ 1

6–

20or

1.93

75–

20U

N2A

0.00

151.

9360

1.92

79..

.1.

9035

1.89

860.

0049

121.

8765

2B1.

883

1.89

51.

9050

1.91

140.

0064

1.93

75(7

)3A

0.00

001.

9375

1.92

94..

.1.

9050

1.90

130.

0037

001.

8780

3B1.

8830

1.89

111.

9050

1.90

980.

0048

1.93

75

2–

4.5

or2.

0000

–4.

5U

NC

1A0.

0029

1.99

711.

9641

...

1.85

281.

8385

0.01

4300

1.73

251B

1.75

91.

795

1.85

571.

8743

0.01

862.

0000

2A0.

0029

1.99

711.

9751

1.96

411.

8528

1.84

330.

0095

141.

7325

2B1.

759

1.79

51.

8557

1.86

810.

0124

2.00

003A

0.00

002.

0000

1.97

80..

.1.

8557

1.84

860.

0071

001.

7354

3B1.

7590

1.78

611.

8557

1.86

500.

0093

2.00

00

2–

6or

2.00

00–

6U

N2A

0.00

261.

9974

1.97

92..

.1.

8891

1.88

050.

0085

541.

7989

2B1.

820

1.85

01.

8917

1.90

280.

0111

2.00

003A

0.00

002.

0000

1.98

18..

.1.

8917

1.88

530.

0064

001.

8015

3B1.

8200

1.83

961.

8917

1.90

000.

0083

2.00

00

2–

8or

2.00

00–

8U

N2A

0.00

231.

9977

1.98

271.

9752

1.91

651.

9087

0.00

7761

1.84

892B

1.86

51.

890

1.91

881.

9289

0.01

012.

0000

3A0.

0000

2.00

001.

9850

...

1.91

881.

9130

0.00

5800

1.85

123B

1.86

501.

8797

1.91

881.

9264

0.00

762.

0000

2–

12or

2.00

00–

12U

N2A

0.00

181.

9982

1.98

68..

.1.

9441

1.93

800.

0060

511.

8990

2B1.

910

1.92

81.

9459

1.95

380.

0079

2.00

003A

0.00

002.

0000

1.98

86..

.1.

9459

1.94

140.

0045

001.

9008

3B1.

9100

1.91

981.

9459

1.95

180.

0059

2.00

00

2–

16or

2.00

00–

16U

N2A

0.00

161.

9984

1.98

90..

.1.

9578

1.95

240.

0053

771.

9240

2B1.

932

1.94

61.

9594

1.96

640.

0070

2.00

00(7

)3A

0.00

002.

0000

1.99

06..

.1.

9594

1.95

540.

0040

001.

9256

3B1.

9320

1.94

091.

9594

1.96

460.

0052

2.00

00

2–

20or

2.00

00–

20U

N2A

0.00

151.

9985

1.99

04..

.1.

9660

1.96

110.

0049

321.

9390

2B1.

946

1.95

71.

9675

1.97

390.

0064

2.00

00(7

)3A

0.00

002.

0000

1.99

19..

.1.

9675

1.96

380.

0037

001.

9405

3B1.

9460

1.95

361.

9675

1.97

230.

0048

2.00

00

21 ⁄ 8–

6or

2.12

50–

6U

N2A

0.00

262.

1224

2.10

42..

.2.

0141

2.00

540.

0086

581.

9239

2B1.

945

1.97

52.

0167

2.02

800.

0113

2.12

503A

0.00

002.

1250

2.10

68..

.2.

0167

2.01

020.

0065

001.

9265

3B1.

9450

1.96

462.

0167

2.02

510.

0084

2.12

50

21 ⁄ 8–

8or

2.12

50–

8U

N2A

0.00

242.

1226

2.10

762.

1001

2.04

142.

0335

0.00

7865

1.97

382B

1.99

02.

015

2.04

382.

0540

0.01

022.

1250

3A0.

0000

2.12

502.

1100

...

2.04

382.

0379

0.00

5900

1.97

623B

1.99

002.

0047

2.04

382.

0515

0.00

772.

1250

21 ⁄ 8–

12or

2.12

50–

12U

N2A

0.00

182.

1232

2.11

18..

.2.

0691

2.06

300.

0060

892.

0240

2B2.

035

2.05

32.

0709

2.07

880.

0079

2.12

50(7

)3A

0.00

002.

1250

2.11

36..

.2.

0709

2.06

630.

0046

002.

0258

3B2.

0350

2.04

482.

0709

2.07

680.

0059

2.12

50

21 ⁄ 8–

16or

2.12

50–

16U

N2A

0.00

162.

1234

2.11

40..

.2.

0828

2.07

740.

0054

152.

0490

2B2.

057

2.07

12.

0844

2.09

140.

0070

2.12

50(7

)3A

0.00

002.

1250

2.11

56..

.2.

0844

2.08

030.

0041

002.

0506

3B2.

0570

2.06

592.

0844

2.08

970.

0053

2.12

50

(7)

21 ⁄ 8–

20or

2.12

50–

20U

N2A

0.00

152.

1235

2.11

54..

.2.

0910

2.08

600.

0049

702.

0640

2B2.

071

2.08

22.

0925

2.09

900.

0065

2.12

50(7

)3A

0.00

002.

1250

2.11

69..

.2.

0925

2.08

880.

0037

002.

0655

3B2.

0710

2.07

862.

0925

2.09

730.

0048

2.12

50

23




Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

21 ⁄ 4–

4.5

or2.

2500

–4.

5U

NC

1A0.

0029

2.24

712.

2141

...

2.10

282.

0882

0.01

4600

1.98

251B

2.00

92.

045

2.10

572.

1247

0.01

902.

2500

2A0.

0029

2.24

712.

2251

2.21

412.

1028

2.09

310.

0097

191.

9825

2B2.

009

2.04

52.

1057

2.11

830.

0126

2.25

003A

0.00

002.

2500

2.22

80..

.2.

1057

2.09

840.

0073

001.

9854

3B2.

0090

2.03

612.

1057

2.11

520.

0095

2.25

00

21 ⁄ 4–

6or

2.25

00–

6U

N2A

0.00

262.

2474

2.22

92..

.2.

1391

2.13

030.

0087

592.

0489

2B2.

070

2.10

02.

1417

2.15

310.

0114

2.25

003A

0.00

002.

2500

2.23

18..

.2.

1417

2.13

510.

0066

002.

0515

3B2.

0700

2.08

962.

1417

2.15

020.

0085

2.25

00

21 ⁄ 4–

8or

2.25

00–

8U

N2A

0.00

242.

2476

2.23

262.

2251

2.16

642.

1584

0.00

7966

2.09

882B

2.11

52.

140

2.16

882.

1792

0.01

042.

2500

3A0.

0000

2.25

002.

2350

...

2.16

882.

1628

0.00

6000

2.10

123B

2.11

502.

1297

2.16

882.

1766

0.00

782.

2500

(7)

21 ⁄ 4–

12or

2.25

00–

12U

N2A

0.00

182.

2482

2.23

68..

.2.

1941

2.18

800.

0061

272.

1490

2B2.

160

2.17

82.

1959

2.20

390.

0080

2.25

00(7

)3A

0.00

002.

2500

2.23

86..

.2.

1959

2.19

130.

0046

002.

1508

3B2.

1600

2.16

982.

1959

2.20

190.

0060

2.25

00

(7)

21 ⁄ 4–

16or

2.25

00–

16U

N2A

0.00

162.

2484

2.23

90..

.2.

2078

2.20

230.

0054

532.

1740

2B2.

182

2.19

62.

2094

2.21

650.

0071

2.25

00(7

)3A

0.00

002.

2500

2.24

06..

.2.

2094

2.20

530.

0041

002.

1756

3B2.

1820

2.19

092.

2094

2.21

470.

0053

2.25

00

(7)

21 ⁄ 4–

20or

2.25

00–

20U

N2A

0.00

152.

2485

2.24

04..

.2.

2160

2.21

100.

0050

082.

1890

2B2.

196

2.20

72.

2175

2.22

400.

0065

2.25

00(7

)3A

0.00

002.

2500

2.24

19..

.2.

2175

2.21

370.

0038

002.

1905

3B2.

1960

2.20

362.

2175

2.22

240.

0049

2.25

00

(7)

23 ⁄ 8–

6or

2.37

50–

6U

N2A

0.00

272.

3723

2.35

41..

.2.

2640

2.25

510.

0088

562.

1738

2B2.

195

2.22

52.

2667

2.27

820.

0115

2.37

503A

0.00

002.

3750

2.35

68..

.2.

2667

2.26

010.

0066

002.

1765

3B2.

1950

2.21

462.

2667

2.27

530.

0086

2.37

50

23 ⁄ 8–

8or

2.37

50–

8U

N2A

0.00

242.

3726

2.35

76..

.2.

2914

2.28

330.

0080

632.

2238

2B2.

240

2.26

52.

2938

2.30

430.

0105

2.37

503A

0.00

002.

3750

2.36

00..

.2.

2938

2.28

780.

0060

002.

2262

3B2.

2400

2.25

472.

2938

2.30

170.

0079

2.37

50

(7)

23 ⁄ 8–

12or

2.37

50–

12U

N2A

0.00

182.

3732

2.36

18..

.2.

3191

2.31

290.

0061

622.

2740

2B2.

285

2.30

32.

3209

2.32

890.

0080

2.37

503A

0.00

002.

3750

2.36

36..

.2.

3209

2.31

630.

0046

002.

2758

3B2.

2850

2.29

482.

3209

2.32

690.

0060

2.37

50

(7)

23 ⁄ 8–

16or

2.37

50–

16U

N2A

0.00

162.

3734

2.36

40..

.2.

3328

2.32

730.

0054

882.

2990

2B2.

307

2.32

12.

3344

2.34

150.

0071

2.37

50(7

)3A

0.00

002.

3750

2.36

56..

.2.

3344

2.33

030.

0041

002.

3006

3B2.

3070

2.31

592.

3344

2.33

980.

0054

2.37

50

(7)

23 ⁄ 8–

20or

2.37

50–

20U

N2A

0.00

152.

3735

2.36

54..

.2.

3410

2.33

600.

0050

432.

3140

2B2.

321

2.33

22.

3425

2.34

910.

0066

2.37

50(7

)3A

0.00

002.

3750

2.36

69..

.2.

3425

2.33

870.

0038

002.

3155

3B2.

3210

2.32

862.

3425

2.34

740.

0049

2.37

50

21 ⁄ 2–

4or

2.50

00–

4U

NC

1A0.

0031

2.49

692.

4612

...

2.33

452.

3190

0.01

5500

2.19

921B

2.22

92.

267

2.33

762.

3578

0.02

022.

5000

2A0.

0031

2.49

692.

4731

2.46

122.

3345

2.32

410.

0103

612.

1992

2B2.

229

2.26

72.

3376

2.35

110.

0135

2.50

003A

0.00

002.

5000

2.47

62..

.2.

3376

2.32

980.

0078

002.

2023

3B2.

2290

2.25

942.

3376

2.34

770.

0101

2.50

00

24


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

21 ⁄ 2–

6or

2.50

00–

6U

N2A

0.00

272.

4973

2.47

91..

.2.

3890

2.38

000.

0089

512.

2988

2B2.

320

2.35

02.

3917

2.40

330.

0116

2.50

003A

0.00

002.

5000

2.48

18..

.2.

3917

2.38

500.

0067

002.

3015

3B2.

3200

2.33

962.

3917

2.40

040.

0087

2.50

00

21 ⁄ 2–

8or

2.50

00–

8U

N2A

0.00

242.

4976

2.48

262.

4751

2.41

642.

4082

0.00

8158

2.34

882B

2.36

52.

390

2.41

882.

4294

0.01

062.

5000

3A0.

0000

2.50

002.

4850

...

2.41

882.

4127

0.00

6100

2.35

123B

2.36

502.

3797

2.41

882.

4268

0.00

802.

5000

21 ⁄ 2–

12or

2.50

00–

12U

N2A

0.00

192.

4981

2.48

67..

.2.

4440

2.43

780.

0061

972.

3989

2B2.

410

2.42

82.

4459

2.45

400.

0081

2.50

003A

0.00

002.

5000

2.48

86..

.2.

4459

2.44

130.

0046

002.

4008

3B2.

4100

2.41

982.

4459

2.45

190.

0060

2.50

00

21 ⁄ 2–

16or

2.50

00–

16U

N2A

0.00

172.

4983

2.48

89..

.2.

4577

2.45

220.

0055

232.

4239

2B2.

432

2.44

62.

4594

2.46

660.

0072

2.50

00(7

)3A

0.00

002.

5000

2.49

06..

.2.

4594

2.45

530.

0041

002.

4256

3B2.

4320

2.44

092.

4594

2.46

480.

0054

2.50

00

21 ⁄ 2–

20or

2.50

00–

20U

N2A

0.00

152.

4985

2.49

04..

.2.

4660

2.46

090.

0050

782.

4390

2B2.

446

2.45

72.

4675

2.47

410.

0066

2.50

00(7

)3A

0.00

002.

5000

2.49

19..

.2.

4675

2.46

370.

0038

002.

4405

3B2.

4460

2.45

362.

4675

2.47

250.

0050

2.50

00

25 ⁄ 8–

6or

2.62

50–

6U

N2A

0.00

272.

6223

2.60

41..

.2.

5140

2.50

500.

0090

422.

4238

2B2.

445

2.47

52.

5167

2.52

850.

0118

2.62

503A

0.00

002.

6250

2.60

68..

.2.

5167

2.50

990.

0068

002.

4265

3B2.

4450

2.46

462.

5167

2.52

550.

0088

2.62

50

25 ⁄ 8–

8or

2.62

50–

8U

N2A

0.00

252.

6225

2.60

75..

.2.

5413

2.53

310.

0082

492.

4737

2B2.

490

2.51

52.

5438

2.55

450.

0107

2.62

503A

0.00

002.

6250

2.61

00..

.2.

5438

2.53

760.

0062

002.

4762

3B2.

4900

2.50

472.

5438

2.55

180.

0080

2.62

50

(7)

25 ⁄ 8–

12or

2.62

50–

12U

N2A

0.00

192.

6231

2.61

17..

.2.

5690

2.56

280.

0062

302.

5239

2B2.

535

2.55

32.

5709

2.57

900.

0081

2.62

503A

0.00

002.

6250

2.61

36..

.2.

5709

2.56

620.

0047

002.

5258

3B2.

5350

2.54

482.

5709

2.57

700.

0061

2.62

50

(7)

25 ⁄ 8–

16or

2.62

50–

16U

N2A

0.00

172.

6233

2.61

39..

.2.

5827

2.57

710.

0055

562.

5489

2B2.

557

2.57

12.

5844

2.59

160.

0072

2.62

50(7

)3A

0.00

002.

6250

2.61

56..

.2.

5844

2.58

020.

0042

002.

5506

3B2.

5570

2.56

592.

5844

2.58

980.

0054

2.62

50

25 ⁄ 8–

20or

2.62

50–

20U

N2A

0.00

152.

6235

2.61

54..

.2.

5910

2.58

590.

0051

112.

5640

2B2.

571

2.58

22.

5925

2.59

910.

0066

2.62

50(7

)3A

0.00

002.

6250

2.61

69..

.2.

5925

2.58

870.

0038

002.

5655

3B2.

5710

2.57

862.

5925

2.59

750.

0050

2.62

50

23 ⁄ 4–

4or

2.75

00–

4U

NC

1A0.

0032

2.74

682.

7111

...

2.58

442.

5686

0.01

5800

2.44

911B

2.47

92.

517

2.58

762.

6082

0.02

062.

7500

2A0.

0032

2.74

682.

7230

2.71

112.

5844

2.57

390.

0105

422.

4491

2B2.

479

2.51

72.

5876

2.60

130.

0137

2.75

003A

0.00

002.

7500

2.72

62..

.2.

5876

2.57

970.

0079

002.

4523

3B2.

4790

2.50

942.

5876

2.59

790.

0103

2.75

00

23 ⁄ 4–

6or

2.75

00–

6U

N2A

0.00

272.

7473

2.72

91..

.2.

6390

2.62

990.

0091

322.

5488

2B2.

570

2.60

02.

6417

2.65

360.

0119

2.75

003A

0.00

002.

7500

2.73

18..

.2.

6417

2.63

490.

0068

002.

5515

3B2.

5700

2.58

962.

6417

2.65

060.

0089

2.75

00

23 ⁄ 4–

8or

2.75

00–

8U

N2A

0.00

252.

7475

2.73

252.

7250

2.66

632.

6580

0.00

8339

2.59

872B

2.61

52.

640

2.66

882.

6796

0.01

082.

7500

3A0.

0000

2.75

002.

7350

...

2.66

882.

6625

0.00

6300

2.60

123B

2.61

502.

6297

2.66

882.

6769

0.00

812.

7500

25




Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(7)

23 ⁄ 4–

12or

2.75

00–

12U

N2A

0.00

192.

7481

2.73

67..

.2.

6940

2.68

770.

0062

632.

6489

2B2.

660

2.67

82.

6959

2.70

400.

0081

2.75

00(7

)3A

0.00

002.

7500

2.73

86..

.2.

6959

2.69

120.

0047

002.

6508

3B2.

6600

2.66

982.

6959

2.70

200.

0061

2.75

00

(7)

23 ⁄ 4–

16or

2.75

00–

16U

N2A

0.00

172.

7483

2.73

89..

.2.

7077

2.70

210.

0055

892.

6739

2B2.

682

2.69

62.

7094

2.71

670.

0073

2.75

00(7

)3A

0.00

002.

7500

2.74

06..

.2.

7094

2.70

520.

0042

002.

6756

3B2.

6820

2.69

092.

7094

2.71

480.

0054

2.75

00

(7)

23 ⁄ 4–

20or

2.75

00–

20U

N2A

0.00

152.

7485

2.74

04..

.2.

7160

2.71

090.

0051

442.

6890

2B2.

696

2.70

72.

7175

2.72

420.

0067

2.75

00(7

)3A

0.00

002.

7500

2.74

19..

.2.

7175

2.71

360.

0039

002.

6905

3B2.

6960

2.70

362.

7175

2.72

250.

0050

2.75

00

27 ⁄ 8–

6or

2.87

50–

6U

N2A

0.00

282.

8722

2.85

40..

.2.

7639

2.75

470.

0092

192.

6737

2B2.

695

2.72

52.

7667

2.77

870.

0120

2.87

503A

0.00

002.

8750

2.85

68..

.2.

7667

2.75

980.

0069

002.

6765

3B2.

6950

2.71

462.

7667

2.77

570.

0090

2.87

50

27 ⁄ 8–

8or

2.87

50–

8U

N2A

0.00

252.

8725

2.85

75..

.2.

7913

2.78

290.

0084

262.

7237

2B2.

740

2.76

52.

7938

2.80

480.

0110

2.87

503A

0.00

002.

8750

2.86

00..

.2.

7938

2.78

750.

0063

002.

7262

3B2.

7400

2.75

472.

7938

2.80

200.

0082

2.87

50

27 ⁄ 8–

12or

2.87

50–

12U

N2A

0.00

192.

8731

2.86

17..

.2.

8190

2.81

270.

0062

942.

7739

2B2.

785

2.80

32.

8209

2.82

910.

0082

2.87

50(7

)3A

0.00

002.

8750

2.86

36..

.2.

8209

2.81

620.

0047

002.

7758

3B2.

7850

2.79

482.

8209

2.82

700.

0061

2.87

50

27 ⁄ 8–

16or

2.87

50–

16U

N2A

0.00

172.

8733

2.86

39..

.2.

8327

2.82

710.

0056

202.

7989

2B2.

807

2.82

12.

8344

2.84

170.

0073

2.87

50(7

)3A

0.00

002.

8750

2.86

56..

.2.

8344

2.83

020.

0042

002.

8006

3B2.

8070

2.81

592.

8344

2.83

990.

0055

2.87

50

(7)

27 ⁄ 8–

20or

2.87

50–

20U

N2A

0.00

162.

8734

2.86

53..

.2.

8409

2.83

570.

0051

752.

8139

2B2.

821

2.83

22.

8425

2.84

920.

0067

2.87

50(7

)3A

0.00

002.

8750

2.86

69..

.2.

8425

2.83

860.

0039

002.

8155

3B2.

8210

2.82

862.

8425

2.84

750.

0050

2.87

50

3–

4or

3.00

00–

4U

NC

1A0.

0032

2.99

682.

9611

...

2.83

442.

8183

0.01

6100

2.69

911B

2.72

92.

767

2.83

762.

8585

0.02

093.

0000

2A0.

0032

2.99

682.

9730

2.96

112.

8344

2.82

370.

0107

142.

6991

2B2.

729

2.76

72.

8376

2.85

150.

0139

3.00

003A

0.00

003.

0000

2.97

62..

.2.

8376

2.82

960.

0080

002.

7023

3B2.

7290

2.75

942.

8376

2.84

800.

0104

3.00

00

3–

6or

3.00

00–

6U

N2A

0.00

282.

9972

2.97

90..

.2.

8889

2.87

960.

0093

042.

7987

2B2.

820

2.85

02.

8917

2.90

380.

0121

3.00

003A

0.00

003.

0000

2.98

18..

.2.

8917

2.88

470.

0070

002.

8015

3B2.

8200

2.83

962.

8917

2.90

080.

0091

3.00

00

3–

8or

3.00

00–

8U

N2A

0.00

262.

9974

2.98

242.

9749

2.91

622.

9077

0.00

8511

2.84

862B

2.86

52.

890

2.91

882.

9299

0.01

113.

0000

3A0.

0000

3.00

002.

9850

...

2.91

882.

9124

0.00

6400

2.85

123B

2.86

502.

8797

2.91

882.

9271

0.00

833.

0000

3–

12or

3.00

00–

12U

N2A

0.00

192.

9981

2.98

67..

.2.

9440

2.93

770.

0063

242.

8989

2B2.

910

2.92

82.

9459

2.95

410.

0082

3.00

003A

0.00

003.

0000

2.98

86..

.2.

9459

2.94

120.

0047

002.

9008

3B2.

9100

2.91

982.

9459

2.95

210.

0062

3.00

00

(7)

3–

16or

3.00

00–

16U

N2A

0.00

172.

9983

2.98

89..

.2.

9577

2.95

210.

0056

502.

9239

2B2.

932

2.94

62.

9594

2.96

670.

0073

3.00

00(7

)3A

0.00

003.

0000

2.99

06..

.2.

9594

2.95

520.

0042

002.

9256

3B2.

9320

2.94

092.

9594

2.96

490.

0055

3.00

00

26


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

3–

20or

3.00

00–

20U

N2A

0.00

162.

9984

2.99

03..

.2.

9659

2.96

070.

0052

052.

9389

2B2.

946

2.95

72.

9675

2.97

430.

0068

3.00

00(7

)3A

0.00

003.

0000

2.99

19..

.2.

9675

2.96

360.

0039

002.

9405

3B2.

9460

2.95

362.

9675

2.97

260.

0051

3.00

00

31 ⁄ 8–

6or

3.12

50–

6U

N2A

0.00

283.

1222

3.10

40..

.3.

0139

3.00

450.

0093

882.

9237

2B2.

945

2.97

53.

0167

3.02

890.

0122

3.12

503A

0.00

003.

1250

3.10

68..

.3.

0167

3.00

970.

0070

002.

9265

3B2.

9450

2.96

463.

0167

3.02

590.

0092

3.12

50

31 ⁄ 8–

8or

3.12

50–

8U

N2A

0.00

263.

1224

3.10

74..

.3.

0412

3.03

260.

0085

952.

9736

2B2.

990

3.01

53.

0438

3.05

500.

0112

3.12

503A

0.00

003.

1250

3.11

00..

.3.

0438

3.03

740.

0064

002.

9762

3B2.

9900

3.00

473.

0438

3.05

220.

0084

3.12

50

(7)

31 ⁄ 8–

12or

3.12

50–

12U

N2A

0.00

193.

1231

3.11

17..

.3.

0690

3.06

260.

0063

543.

0239

2B3.

035

3.05

33.

0709

3.07

920.

0083

3.12

50(7

)3A

0.00

003.

1250

3.11

36..

.3.

0709

3.06

610.

0048

003.

0258

3B3.

0350

3.04

483.

0709

3.07

710.

0062

3.12

50

(7)

31 ⁄ 8–

16or

3.12

50–

16U

N2A

0.00

173.

1233

3.11

39..

.3.

0827

3.07

700.

0056

803.

0489

2B3.

057

3.07

13.

0844

3.09

180.

0074

3.12

50(7

)3A

0.00

003.

1250

3.11

56..

.3.

0844

3.08

010.

0043

003.

0506

3B3.

0570

3.06

593.

0844

3.08

990.

0055

3.12

50

31 ⁄ 4–

4or

3.25

00–

4U

NC

1A0.

0033

3.24

673.

2110

...

3.08

433.

0680

0.01

6300

2.94

901B

2.97

93.

017

3.08

763.

1088

0.02

123.

2500

2A0.

0033

3.24

673.

2229

3.21

103.

0843

3.07

340.

0108

792.

9490

2B2.

979

3.01

73.

0876

3.10

170.

0141

3.25

003A

0.00

003.

2500

3.22

62..

.3.

0876

3.07

940.

0082

002.

9523

3B2.

9790

3.00

943.

0876

3.09

820.

0106

3.25

00

31 ⁄ 4–

6or

3.25

00–

6U

N2A

0.00

283.

2472

3.22

90..

.3.

1389

3.12

940.

0094

693.

0487

2B3.

070

3.10

03.

1417

3.15

400.

0123

3.25

003A

0.00

003.

2500

3.23

18..

.3.

1417

3.13

460.

0071

003.

0515

3B3.

0700

3.08

963.

1417

3.15

090.

0092

3.25

00

31 ⁄ 4–

8or

3.25

00–

8U

N2A

0.00

263.

2474

3.23

243.

2249

3.16

623.

1575

0.00

8676

3.09

862B

3.11

53.

140

3.16

883.

1801

0.01

133.

2500

3A0.

0000

3.25

003.

2350

...

3.16

883.

1623

0.00

6500

3.10

123B

3.11

503.

1297

3.16

883.

1773

0.00

853.

2500

(7)

31 ⁄ 4–

12or

3.25

00–

12U

N2A

0.00

193.

2481

3.23

67..

.3.

1940

3.18

760.

0063

833.

1489

2B3.

160

3.17

83.

1959

3.20

420.

0083

3.25

00(7

)3A

0.00

003.

2500

3.23

86..

.3.

1959

3.19

110.

0048

003.

1508

3B3.

1600

3.16

983.

1959

3.20

210.

0062

3.25

00

(7)

31 ⁄ 4–

16or

3.25

00–

16U

N2A

0.00

173.

2483

3.23

89..

.3.

2077

3.20

200.

0057

093.

1739

2B3.

182

3.19

63.

2094

3.21

680.

0074

3.25

00(7

)3A

0.00

003.

2500

3.24

06..

.3.

2094

3.20

510.

0043

003.

1756

3B3.

1820

3.19

093.

2094

3.21

500.

0056

3.25

00

33 ⁄ 8–

6or

3.37

50–

6U

N2A

0.00

293.

3721

3.35

39..

.3.

2638

3.25

430.

0095

493.

1736

2B3.

195

3.22

53.

2667

3.27

910.

0124

3.37

503A

0.00

003.

3750

3.35

68..

.3.

2667

3.25

950.

0072

003.

1765

3B3.

1950

3.21

463.

2667

3.27

600.

0093

3.37

50

33 ⁄ 8–

8or

3.37

50–

8U

N2A

0.00

263.

3724

3.35

74..

.3.

2912

3.28

240.

0087

563.

2236

2B3.

240

3.26

53.

2938

3.30

520.

0114

3.37

503A

0.00

003.

3750

3.36

00..

.3.

2938

3.28

720.

0066

003.

2262

3B3.

2400

3.25

473.

2938

3.30

230.

0085

3.37

50

(7)

33 ⁄ 8–

12or

3.37

50–

12U

N2A

0.00

193.

3731

3.36

17..

.3.

3190

3.31

260.

0064

113.

2739

2B3.

285

3.30

33.

3209

3.32

920.

0083

3.37

503A

0.00

003.

3750

3.36

36..

.3.

3209

3.31

610.

0048

003.

2758

3B3.

2850

3.29

483.

3209

3.32

720.

0063

3.37

50

27




Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(7)

33 ⁄ 8–

16or

3.37

50–

16U

N2A

0.00

173.

3733

3.36

39..

.3.

3327

3.32

700.

0057

373.

2989

2B3.

307

3.32

13.

3344

3.34

190.

0075

3.37

50(7

)3A

0.00

003.

3750

3.36

56..

.3.

3344

3.33

010.

0043

003.

3006

3B3.

3070

3.31

593.

3344

3.34

000.

0056

3.37

50

31 ⁄ 2–

4or

3.50

00–

4U

NC

1A0.

0033

3.49

673.

4610

...

3.33

433.

3177

0.01

6600

3.19

901B

3.22

93.

267

3.33

763.

3591

0.02

153.

5000

2A0.

0033

3.49

673.

4729

3.46

103.

3343

3.32

330.

0110

363.

1990

2B3.

229

3.26

73.

3376

3.35

190.

0143

3.50

003A

0.00

003.

5000

3.47

62..

.3.

3376

3.32

930.

0083

003.

2023

3B3.

2290

3.25

943.

3376

3.34

840.

0108

3.50

00

31 ⁄ 2–

6or

3.50

00–

6U

N2A

0.00

293.

4971

3.47

89..

.3.

3888

3.37

920.

0096

263.

2986

2B3.

320

3.35

03.

3917

3.40

420.

0125

3.50

003A

0.00

003.

5000

3.48

18..

.3.

3917

3.38

450.

0072

003.

3015

3B3.

3200

3.33

963.

3917

3.40

110.

0094

3.50

00

31 ⁄ 2–

8or

3.50

00–

8U

N2A

0.00

263.

4974

3.48

243.

4749

3.41

623.

4074

0.00

8833

3.34

862B

3.36

53.

390

3.41

883.

4303

0.01

153.

5000

3A0.

0000

3.50

003.

4850

...

3.41

883.

4122

0.00

6600

3.35

123B

3.36

503.

3797

3.41

883.

4274

0.00

863.

5000

31 ⁄ 2–

12or

3.50

00–

12U

N2A

0.00

193.

4981

3.48

67..

.3.

4440

3.43

760.

0064

383.

3989

2B3.

410

3.42

83.

4459

3.45

430.

0084

3.50

003A

0.00

003.

5000

3.48

86..

.3.

4459

3.44

110.

0048

003.

4008

3B3.

4100

3.41

983.

4459

3.45

220.

0063

3.50

00

31 ⁄ 2–

16or

3.50

00–

16U

N2A

0.00

173.

4983

3.48

89..

.3.

4577

3.45

190.

0057

643.

4239

2B3.

432

3.44

63.

4594

3.46

690.

0075

3.50

00(7

)3A

0.00

003.

5000

3.49

06..

.3.

4594

3.45

510.

0043

003.

4256

3B3.

4320

3.44

093.

4594

3.46

500.

0056

3.50

00

35 ⁄ 8–

6or

3.62

50–

6U

N2A

0.00

293.

6221

3.60

39..

.3.

5138

3.50

410.

0097

033.

4236

2B3.

445

3.47

53.

5167

3.52

930.

0126

3.62

503A

0.00

003.

6250

3.60

68..

.3.

5167

3.50

940.

0073

003.

4265

3B3.

4450

3.46

463.

5167

3.52

620.

0095

3.62

50

35 ⁄ 8–

8or

3.62

50–

8U

N2A

0.00

273.

6223

3.60

73..

.3.

5411

3.53

220.

0089

103.

4735

2B3.

490

3.51

53.

5438

3.55

540.

0116

3.62

503A

0.00

003.

6250

3.61

00..

.3.

5438

3.53

710.

0067

003.

4762

3B3.

4900

3.50

473.

5438

3.55

250.

0087

3.62

50

35 ⁄ 8–

12or

3.62

50–

12U

N2A

0.00

193.

6231

3.61

17..

.3.

5690

3.56

250.

0064

653.

5239

2B3.

535

3.55

33.

5709

3.57

930.

0084

3.62

50(7

)3A

0.00

003.

6250

3.61

36..

.3.

5709

3.56

610.

0048

003.

5258

3B3.

5350

3.54

483.

5709

3.57

720.

0063

3.62

50

(7)

35 ⁄ 8–

16or

3.62

50–

16U

N2A

0.00

173.

6233

3.61

39..

.3.

5827

3.57

690.

0057

913.

5489

2B3.

557

3.57

13.

5844

3.59

190.

0075

3.62

503A

0.00

003.

6250

3.61

56..

.3.

5844

3.58

010.

0043

003.

5506

3B3.

5570

3.56

593.

5844

3.59

000.

0056

3.62

50

33 ⁄ 4–

4or

3.75

00–

4U

NC

1A0.

0034

3.74

663.

7109

...

3.58

423.

5674

0.01

6800

3.44

891B

3.47

93.

517

3.58

763.

6094

0.02

183.

7500

2A0.

0034

3.74

663.

7228

3.71

093.

5842

3.57

300.

0111

883.

4489

2B3.

479

3.51

73.

5876

3.60

210.

0145

3.75

003A

0.00

003.

7500

3.72

62..

.3.

5876

3.57

920.

0084

003.

4523

3B3.

4790

3.50

943.

5876

3.59

850.

0109

3.75

00

33 ⁄ 4–

6or

3.75

00–

6U

N2A

0.00

293.

7471

3.72

89..

.3.

6388

3.62

900.

0097

783.

5486

2B3.

570

3.60

03.

6417

3.65

440.

0127

3.75

003A

0.00

003.

7500

3.73

18..

.3.

6417

3.63

440.

0073

003.

5515

3B3.

5700

3.58

963.

6417

3.65

120.

0095

3.75

00

28


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

33 ⁄ 4–

8or

3.75

00–

8U

N2A

0.00

273.

7473

3.73

233.

7248

3.66

613.

6571

0.00

8985

3.59

852B

3.61

53.

640

3.66

883.

6805

0.01

173.

7500

3A0.

0000

3.75

003.

7350

...

3.66

883.

6621

0.00

6700

3.60

123B

3.61

503.

6297

3.66

883.

6776

0.00

883.

7500

(7)

33 ⁄ 4–

12or

3.75

00–

12U

N2A

0.00

193.

7481

3.73

67..

.3.

6940

3.68

750.

0064

913.

6489

2B3.

660

3.67

83.

6959

3.70

430.

0084

3.75

00(7

)3A

0.00

003.

7500

3.73

86..

.3.

6959

3.69

100.

0049

003.

6508

3B3.

6600

3.66

983.

6959

3.70

220.

0063

3.75

00

(7)

33 ⁄ 4–

16or

3.75

00–

16U

N2A

0.00

173.

7483

3.73

89..

.3.

7077

3.70

190.

0058

173.

6739

2B3.

682

3.69

63.

7094

3.71

700.

0076

3.75

00(7

)3A

0.00

003.

7500

3.74

06..

.3.

7094

3.70

500.

0044

003.

6756

3B3.

6820

3.69

093.

7094

3.71

510.

0057

3.75

00

37 ⁄ 8–

6or

3.87

50–

6U

N2A

0.00

303.

8720

3.85

38..

.3.

7637

3.75

380.

0098

523.

6735

2B3.

695

3.72

53.

7667

3.77

950.

0128

3.87

503A

0.00

003.

8750

3.85

68..

.3.

7667

3.75

930.

0074

003.

6765

3B3.

6950

3.71

463.

7667

3.77

630.

0096

3.87

50

37 ⁄ 8–

8or

3.87

50–

8U

N2A

0.00

273.

8723

3.85

73..

.3.

7911

3.78

200.

0090

593.

7235

2B3.

740

3.76

53.

7938

3.80

560.

0118

3.87

503A

0.00

003.

8750

3.86

00..

.3.

7938

3.78

700.

0068

003.

7262

3B3.

7400

3.75

473.

7938

3.80

260.

0088

3.87

50

37 ⁄ 8–

12or

3.87

50–

12U

N2A

0.00

203.

8730

3.86

16..

.3.

8189

3.81

240.

0065

173.

7738

2B3.

785

3.80

33.

8209

3.82

940.

0085

3.87

503A

0.00

003.

8750

3.86

36..

.3.

8209

3.81

600.

0049

003.

7758

3B3.

7850

3.79

483.

8209

3.82

730.

0064

3.87

50

(7)

37 ⁄ 8–

16or

3.87

50–

16U

N2A

0.00

183.

8732

3.86

38..

.3.

8326

3.82

680.

0058

433.

7988

2B3.

807

3.82

13.

8344

3.84

200.

0076

3.87

50(7

)3A

0.00

003.

8750

3.86

56..

.3.

8344

3.83

000.

0044

003.

8006

3B3.

8070

3.81

593.

8344

3.84

010.

0057

3.87

50

4–

4or

4.00

00–

4U

NC

1A0.

0034

3.99

663.

9609

...

3.83

423.

8172

0.01

7000

3.69

891B

3.72

93.

767

3.83

763.

8597

0.02

214.

0000

2A0.

0034

3.99

663.

9728

3.96

093.

8342

3.82

290.

0113

343.

6989

2B3.

729

3.76

73.

8376

3.85

230.

0147

4.00

003A

0.00

004.

0000

3.97

62..

.3.

8376

3.82

910.

0085

003.

7023

3B3.

7290

3.75

943.

8376

3.84

870.

0111

4.00

00

4–

6or

4.00

00–

6U

N2A

0.00

303.

9970

3.97

88..

.3.

8887

3.87

880.

0099

243.

7985

2B3.

820

3.85

03.

8917

3.90

460.

0129

4.00

003A

0.00

004.

0000

3.98

18..

.3.

8917

3.88

430.

0074

003.

8015

3B3.

8200

3.83

963.

8917

3.90

140.

0097

4.00

00

4–

8or

4.00

00–

8U

N2A

0.00

273.

9973

3.98

233.

9748

3.91

613.

9070

0.00

9131

3.84

852B

3.86

53.

890

3.91

883.

9307

0.01

194.

0000

3A0.

0000

4.00

003.

9850

...

3.91

883.

9120

0.00

6800

3.85

123B

3.86

503.

8797

3.91

883.

9277

0.00

894.

0000

4–

12or

4.00

00–

12U

N2A

0.00

203.

9980

3.98

66..

.3.

9439

3.93

740.

0065

423.

8988

2B3.

910

3.92

83.

9459

3.95

440.

0085

4.00

003A

0.00

004.

0000

3.98

86..

.3.

9459

3.94

100.

0049

003.

9008

3B3.

9100

3.91

983.

9459

3.95

230.

0064

4.00

00

4–

16or

4.00

00–

16U

N2A

0.00

183.

9982

3.98

88..

.3.

9576

3.95

170.

0058

683.

9238

2B3.

932

3.94

63.

9594

3.96

700.

0076

4.00

00(7

)3A

0.00

004.

0000

3.99

06..

.3.

9594

3.95

500.

0044

003.

9256

3B3.

9320

3.94

093.

9594

3.96

510.

0057

4.00

00

41 ⁄ 8–

6or

4.12

50–

6U

N2A

0.00

304.

1220

4.10

38..

.4.

0137

4.00

370.

0099

963.

9235

2B3.

945

3.97

54.

0167

4.02

970.

0130

4.12

503A

0.00

004.

1250

4.10

68..

.4.

0167

4.00

920.

0075

003.

9265

3B3.

9450

3.96

464.

0167

4.02

640.

0097

4.12

50

29




Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]M

inor

Func

tion

alD

iam

eter

Ser

ies

Max

.M

ajor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

41 ⁄ 8–

8or

4.12

50–

8U

N2A

0.00

284.

1222

4.10

72..

.4.

0410

4.03

180.

0092

033.

9734

2B3.

990

4.01

54.

0438

4.05

580.

0120

4.12

503A

0.00

004.

1250

4.11

00..

.4.

0438

4.03

690.

0069

003.

9762

3B3.

9900

4.00

474.

0438

4.05

280.

0090

4.12

50

(7)

41 ⁄ 8–

12or

4.12

50–

12U

N2A

0.00

204.

1230

4.11

16..

.4.

0689

4.06

230.

0065

674.

0238

2B4.

035

4.05

34.

0709

4.07

940.

0085

4.12

503A

0.00

004.

1250

4.11

36..

.4.

0709

4.06

600.

0049

004.

0258

3B4.

0350

4.04

484.

0709

4.07

730.

0064

4.12

50

(7)

41 ⁄ 8–

16or

4.12

50–

16U

N2A

0.00

184.

1232

4.11

38..

.4.

0826

4.07

670.

0058

934.

0488

2B4.

057

4.07

14.

0844

4.09

210.

0077

4.12

50(7

)3A

0.00

004.

1250

4.11

56..

.4.

0844

4.08

000.

0044

004.

0506

3B4.

0570

4.06

594.

0844

4.09

010.

0057

4.12

50

41 ⁄ 4–

4or

4.25

00–

4U

N2A

0.00

344.

2466

4.22

28..

.4.

0842

4.07

270.

0114

753.

9489

2B3.

979

4.01

74.

0876

4.10

250.

0149

4.25

003A

0.00

004.

2500

4.22

62..

.4.

0876

4.07

900.

0086

003.

9523

3B3.

9790

4.00

944.

0876

4.09

880.

0112

4.25

00

41 ⁄ 4–

6or

4.25

00–

6U

N2A

0.00

304.

2470

4.22

88..

.4.

1387

4.12

860.

0100

654.

0485

2B4.

070

4.10

04.

1417

4.15

480.

0131

4.25

003A

0.00

004.

2500

4.23

18..

.4.

1417

4.13

420.

0075

004.

0515

3B4.

0700

4.08

964.

1417

4.15

150.

0098

4.25

00

(7)

41 ⁄ 4–

8or

4.25

00–

8U

N2A

0.00

284.

2472

4.23

22..

.4.

1660

4.15

670.

0092

724.

0984

2B4.

115

4.14

04.

1688

4.18

090.

0121

4.25

00(7

)3A

0.00

004.

2500

4.23

50..

.4.

1688

4.16

180.

0070

004.

1012

3B4.

1150

4.12

974.

1688

4.17

780.

0090

4.25

00

(7)

41 ⁄ 4–

12or

4.25

00–

12U

N2A

0.00

204.

2480

4.23

66..

.4.

1939

4.18

730.

0065

914.

1488

2B4.

160

4.17

84.

1959

4.20

450.

0086

4.25

003A

0.00

004.

2500

4.23

86..

.4.

1959

4.19

100.

0049

004.

1508

3B4.

1600

4.16

984.

1959

4.20

230.

0064

4.25

00

(7)

41 ⁄ 4–

16or

4.25

00–

16U

N2A

0.00

184.

2482

4.23

88..

.4.

2076

4.20

170.

0059

174.

1738

2B4.

182

4.19

64.

2094

4.21

710.

0077

4.25

00(7

)3A

0.00

004.

2500

4.24

06..

.4.

2094

4.20

500.

0044

004.

1756

3B4.

1820

4.19

094.

2094

4.21

520.

0058

4.25

00

43 ⁄ 8–

6or

4.37

50–

6U

N2A

0.00

304.

3720

4.35

38..

.4.

2637

4.25

360.

0101

334.

1735

2B4.

195

4.22

54.

2667

4.27

990.

0132

4.37

503A

0.00

004.

3750

4.35

68..

.4.

2667

4.25

910.

0076

004.

1765

3B4.

1950

4.21

464.

2667

4.27

660.

0099

4.37

50

(7)

43 ⁄ 8–

8or

4.37

50–

8U

N2A

0.00

284.

3722

4.35

72..

.4.

2910

4.28

170.

0093

404.

2234

2B4.

240

4.26

54.

2938

4.30

590.

0121

4.37

503A

0.00

004.

3750

4.36

00..

.4.

2938

4.28

680.

0070

004.

2262

3B4.

2400

4.25

474.

2938

4.30

290.

0091

4.37

50

(7)

43 ⁄ 8–

12or

4.37

50–

12U

N2A

0.00

204.

3730

4.36

16..

.4.

3189

4.31

230.

0066

144.

2738

2B4.

285

4.30

34.

3209

4.32

950.

0086

4.37

50(7

)3A

0.00

004.

3750

4.36

36..

.4.

3209

4.31

590.

0050

004.

2758

3B4.

2850

4.29

484.

3209

4.32

730.

0064

4.37

50

(7)

43 ⁄ 8–

16or

4.37

50–

16U

N2A

0.00

184.

3732

4.36

38..

.4.

3326

4.32

670.

0059

404.

2988

2B4.

307

4.32

14.

3344

4.34

210.

0077

4.37

50(7

)3A

0.00

004.

3750

4.36

56..

.4.

3344

4.32

990.

0045

004.

3006

3B4.

3070

4.31

594.

3344

4.34

020.

0058

4.37

50

41 ⁄ 2–

4or

4.50

00–

4U

N2A

0.00

354.

4965

4.47

27..

.4.

3341

4.32

250.

0116

114.

1988

2B4.

229

4.26

74.

3376

4.35

270.

0151

4.50

003A

0.00

004.

5000

4.47

62..

.4.

3376

4.32

890.

0087

004.

2023

3B4.

2290

4.25

944.

3376

4.34

890.

0113

4.50

00

30


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

41 ⁄ 2–

6or

4.50

00–

6U

N2A

0.00

314.

4969

4.47

87..

.4.

3886

4.37

840.

0102

014.

2984

2B4.

320

4.35

04.

3917

4.40

500.

0133

4.50

003A

0.00

004.

5000

4.48

18..

.4.

3917

4.38

400.

0077

004.

3015

3B4.

3200

4.33

964.

3917

4.40

160.

0099

4.50

00

41 ⁄ 2–

8or

4.50

00–

8U

N2A

0.00

284.

4972

4.48

22..

.4.

4160

4.40

660.

0094

084.

3484

2B4.

365

4.39

04.

4188

4.43

100.

0122

4.50

003A

0.00

004.

5000

4.48

50..

.4.

4188

4.41

170.

0071

004.

3512

3B4.

3650

4.37

974.

4188

4.42

800.

0092

4.50

00

(7)

41 ⁄ 2–

12or

4.50

00–

12U

N2A

0.00

204.

4980

4.48

66..

.4.

4439

4.43

730.

0066

374.

3988

2B4.

410

4.42

84.

4459

4.45

450.

0086

4.50

00(7

)3A

0.00

004.

5000

4.48

86..

.4.

4459

4.44

090.

0050

004.

4008

3B4.

4100

4.41

984.

4459

4.45

240.

0065

4.50

00

(7)

41 ⁄ 2–

16or

4.50

00–

16U

N2A

0.00

184.

4982

4.48

88..

.4.

4576

4.45

160.

0059

634.

4238

2B4.

432

4.44

64.

4594

4.46

720.

0078

4.50

00(7

)3A

0.00

004.

5000

4.49

06..

.4.

4594

4.45

490.

0045

004.

4256

3B4.

4320

4.44

094.

4594

4.46

520.

0058

4.50

00

45 ⁄ 8–

6or

4.62

50–

6U

N2A

0.00

314.

6219

4.60

37..

.4.

5136

4.50

330.

0102

684.

4234

2B4.

445

4.47

54.

5167

4.53

000.

0133

4.62

503A

0.00

004.

6250

4.60

68..

.4.

5167

4.50

900.

0077

004.

4265

3B4.

4450

4.46

464.

5167

4.52

670.

0100

4.62

50

(7)

45 ⁄ 8–

8or

4.62

50–

8U

N2A

0.00

284.

6222

4.60

72..

.4.

5410

4.53

150.

0094

754.

4734

2B4.

490

4.51

54.

5438

4.55

610.

0123

4.62

50(7

)3A

0.00

004.

6250

4.61

00..

.4.

5438

4.53

670.

0071

004.

4762

3B4.

4900

4.50

474.

5438

4.55

300.

0092

4.62

50

45 ⁄ 8–

12or

4.62

50–

12U

N2A

0.00

204.

6230

4.61

16..

.4.

5689

4.56

220.

0066

604.

5238

2B4.

535

4.55

34.

5709

4.57

960.

0087

4.62

50(7

)3A

0.00

004.

6250

4.61

36..

.4.

5709

4.56

590.

0050

004.

5258

3B4.

5350

4.54

484.

5709

4.57

740.

0066

4.62

50

(7)

45 ⁄ 8–

16or

4.62

50–

16U

N2A

0.00

184.

6232

4.61

38..

.4.

5826

4.57

660.

0059

864.

5488

2B4.

557

4.57

14.

5844

4.59

220.

0078

4.62

50(7

)3A

0.00

004.

6250

4.61

56..

.4.

5844

4.57

990.

0045

004.

5506

3B4.

5570

4.56

594.

5844

4.59

020.

0058

4.62

50

43 ⁄ 4–

4or

4.75

00–

4U

N2A

0.00

354.

7465

4.72

27..

.4.

5841

4.57

240.

0117

434.

4488

2B4.

479

4.51

74.

5876

4.60

290.

0153

4.75

003A

0.00

004.

7500

4.72

62..

.4.

5876

4.57

880.

0088

004.

4523

3B4.

4790

4.50

944.

5876

4.59

900.

0114

4.75

00

43 ⁄ 4–

6or

4.75

00–

6U

N2A

0.00

314.

7469

4.72

87..

.4.

6386

4.62

830.

0103

334.

5484

2B4.

570

4.60

04.

6417

4.65

510.

0134

4.75

003A

0.00

004.

7500

4.73

18..

.4.

6417

4.63

400.

0077

004.

5515

3B4.

5700

4.58

964.

6417

4.65

180.

0101

4.75

00

43 ⁄ 4–

8or

4.75

00–

8U

N2A

0.00

294.

7471

4.73

21..

.4.

6659

4.65

640.

0095

404.

5983

2B4.

615

4.64

04.

6688

4.68

120.

0124

4.75

00(7

)3A

0.00

004.

7500

4.73

50..

.4.

6688

4.66

160.

0072

004.

6012

3B4.

6150

4.62

974.

6688

4.67

810.

0093

4.75

00

43 ⁄ 4–

12or

4.75

00–

12U

N2A

0.00

204.

7480

4.73

66..

.4.

6939

4.68

720.

0066

824.

6488

2B4.

660

4.67

84.

6959

4.70

460.

0087

4.75

00(7

)3A

0.00

004.

7500

4.73

86..

.4.

6959

4.69

090.

0050

004.

6508

3B4.

6600

4.66

984.

6959

4.70

240.

0065

4.75

00

(7)

43 ⁄ 4–

16or

4.75

00–

16U

N2A

0.00

184.

7482

4.73

88..

.4.

7076

4.70

160.

0060

084.

6738

2B4.

682

4.69

64.

7094

4.71

720.

0078

4.75

00(7

)3A

0.00

004.

7500

4.74

06..

.4.

7094

4.70

490.

0045

004.

6756

3B4.

6820

4.69

094.

7094

4.71

530.

0059

4.75

00

31




Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

47 ⁄ 8–

6or

4.87

50–

6U

N2A

0.00

314.

8719

4.85

37..

.4.

7636

4.75

320.

0103

984.

6734

2B4.

695

4.72

54.

7667

4.78

020.

0135

4.87

503A

0.00

004.

8750

4.85

68..

.4.

7667

4.75

890.

0078

004.

6765

3B4.

6950

4.71

464.

7667

4.77

680.

0101

4.87

50

47 ⁄ 8–

8or

4.87

50–

8U

N2A

0.00

294.

8721

4.85

71..

.4.

7909

4.78

130.

0096

054.

7233

2B4.

740

4.76

54.

7938

4.80

630.

0125

4.87

503A

0.00

004.

8750

4.86

00..

.4.

7938

4.78

660.

0072

004.

7262

3B4.

7400

4.75

474.

7938

4.80

320.

0094

4.87

50

47 ⁄ 8–

12or

4.87

50–

12U

N2A

0.00

204.

8730

4.86

16..

.4.

8189

4.81

220.

0067

044.

7738

2B4.

785

4.80

34.

8209

4.82

960.

0087

4.87

50(7

)3A

0.00

004.

8750

4.86

36..

.4.

8209

4.81

590.

0050

004.

7758

3B4.

7850

4.79

484.

8209

4.82

740.

0065

4.87

50

(7)

47 ⁄ 8–

16or

4.87

50–

16U

N2A

0.00

184.

8732

4.86

38..

.4.

8326

4.82

660.

0060

304.

7988

2B4.

807

4.82

14.

8344

4.84

220.

0078

4.87

50(7

)3A

0.00

004.

8750

4.86

56..

.4.

8344

4.82

990.

0045

004.

8006

3B4.

8070

4.81

594.

8344

4.84

030.

0059

4.87

50

5–

4or

5.00

00–

4U

N2A

0.00

364.

9964

4.97

26..

.4.

8340

4.82

210.

0118

724.

6987

2B4.

729

4.76

74.

8376

4.85

300.

0154

5.00

003A

0.00

005.

0000

4.97

62..

.4.

8376

4.82

870.

0089

004.

7023

3B4.

7290

4.75

944.

8376

4.84

920.

0116

5.00

00

5–

6or

5.00

00–

6U

N2A

0.00

314.

9969

4.97

87..

.4.

8886

4.87

810.

0104

624.

7984

2B4.

820

4.85

04.

8917

4.90

530.

0136

5.00

003A

0.00

005.

0000

4.98

18..

.4.

8917

4.88

390.

0078

004.

8015

3B4.

8200

4.83

964.

8917

4.90

190.

0102

5.00

00

5–

8or

5.00

00–

8U

N2A

0.00

294.

9971

4.98

21..

.4.

9159

4.90

620.

0096

694.

8483

2B4.

865

4.89

04.

9188

4.93

140.

0126

5.00

00(7

)3A

0.00

005.

0000

4.98

50..

.4.

9188

4.91

150.

0073

004.

8512

3B4.

8650

4.87

974.

9188

4.92

820.

0094

5.00

00

5–

12or

5.00

00–

12U

N2A

0.00

204.

9980

4.98

66..

.4.

9439

4.93

720.

0067

264.

8988

2B4.

910

4.92

84.

9459

4.95

460.

0087

5.00

003A

0.00

005.

0000

4.98

86..

.4.

9459

4.94

090.

0050

004.

9008

3B4.

9100

4.91

984.

9459

4.95

250.

0066

5.00

00

5–

16or

5.00

00–

16U

N2A

0.00

184.

9982

4.98

88..

.4.

9576

4.95

150.

0060

524.

9238

2B4.

932

4.94

64.

9594

4.96

730.

0079

5.00

00(7

)3A

0.00

005.

0000

4.99

06..

.4.

9594

4.95

490.

0045

004.

9256

3B4.

9320

4.94

094.

9594

4.96

530.

0059

5.00

00

51 ⁄ 8–

6or

5.12

50–

6U

N2A

0.00

325.

1218

5.10

36..

.5.

0135

5.00

300.

0105

254.

9233

2B4.

945

4.97

55.

0167

5.03

040.

0137

5.12

503A

0.00

005.

1250

5.10

68..

.5.

0167

5.00

880.

0079

004.

9265

3B4.

9450

4.96

465.

0167

5.02

700.

0103

5.12

50

(7)

51 ⁄ 8–

8or

5.12

50–

8U

N2A

0.00

295.

1221

5.10

71..

.5.

0409

5.03

120.

0097

324.

9733

2B4.

990

5.01

55.

0438

5.05

650.

0127

5.12

503A

0.00

005.

1250

5.11

00..

.5.

0438

5.03

650.

0073

004.

9762

3B4.

9900

5.00

475.

0438

5.05

330.

0095

5.12

50

(7)

51 ⁄ 8–

12or

5.12

50–

12U

N2A

0.00

205.

1230

5.11

16..

.5.

0689

5.06

220.

0067

475.

0238

2B5.

035

5.05

35.

0709

5.07

970.

0088

5.12

50(7

)3A

0.00

005.

1250

5.11

36..

.5.

0709

5.06

580.

0051

005.

0258

3B5.

0350

5.04

485.

0709

5.07

750.

0066

5.12

50

51 ⁄ 8–

16or

5.12

50–

16U

N2A

0.00

185.

1232

5.11

38..

.5.

0826

5.07

650.

0060

735.

0488

2B5.

057

5.07

15.

0844

5.09

230.

0079

5.12

50(7

)3A

0.00

005.

1250

5.11

56..

.5.

0844

5.07

980.

0046

005.

0506

3B5.

0570

5.06

595.

0844

5.09

030.

0059

5.12

50

32


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

51 ⁄ 4–

4or

5.25

00–

4U

N2A

0.00

365.

2464

5.22

26..

.5.

0840

5.07

200.

0119

974.

9487

2B4.

979

5.01

75.

0876

5.10

320.

0156

5.25

003A

0.00

005.

2500

5.22

62..

.5.

0876

5.07

860.

0090

004.

9523

3B4.

9790

5.00

945.

0876

5.09

930.

0117

5.25

00

51 ⁄ 4–

6or

5.25

00–

6U

N2A

0.00

325.

2468

5.22

86..

.5.

1385

5.12

790.

0105

875.

0483

2B5.

070

5.10

05.

1417

5.15

550.

0138

5.25

003A

0.00

005.

2500

5.23

18..

.5.

1417

5.13

380.

0079

005.

0515

3B5.

0700

5.08

965.

1417

5.15

200.

0103

5.25

00

51 ⁄ 4–

8or

5.25

00–

8U

N2A

0.00

295.

2471

5.23

21..

.5.

1659

5.15

610.

0097

945.

0983

2B5.

115

5.14

05.

1688

5.18

150.

0127

5.25

00(7

)3A

0.00

005.

2500

5.23

50..

.5.

1688

5.16

150.

0073

005.

1012

3B5.

1150

5.12

975.

1688

5.17

830.

0095

5.25

00

(7)

51 ⁄ 4–

12or

5.25

00–

12U

N2A

0.00

205.

2480

5.23

66..

.5.

1939

5.18

710.

0067

685.

1488

2B5.

160

5.17

85.

1959

5.20

470.

0088

5.25

00(7

)3A

0.00

005.

2500

5.23

86..

.5.

1959

5.19

080.

0051

005.

1508

3B5.

1600

5.16

985.

1959

5.20

250.

0066

5.25

00

51 ⁄ 4–

16or

5.25

00–

16U

N2A

0.00

185.

2482

5.23

88..

.5.

2076

5.20

150.

0060

945.

1738

2B5.

182

5.19

65.

2094

5.21

730.

0079

5.25

00(7

)3A

0.00

005.

2500

5.24

06..

.5.

2094

5.20

480.

0046

005.

1756

3B5.

1820

5.19

095.

2094

5.21

530.

0059

5.25

00

53 ⁄ 8–

6or

5.37

50–

6U

N2A

0.00

325.

3718

5.35

36..

.5.

2635

5.25

290.

0106

495.

1733

2B5.

195

5.22

55.

2667

5.28

050.

0138

5.37

503A

0.00

005.

3750

5.35

68..

.5.

2667

5.25

870.

0080

005.

1765

3B5.

1950

5.21

465.

2667

5.27

710.

0104

5.37

50

(7)

53 ⁄ 8–

8or

5.37

50–

8U

N2A

0.00

305.

3720

5.35

70..

.5.

2908

5.28

090.

0098

565.

2232

2B5.

240

5.26

55.

2938

5.30

660.

0128

5.37

50(7

)3A

0.00

005.

3750

5.36

00..

.5.

2938

5.28

640.

0074

005.

2262

3B5.

2400

5.25

475.

2938

5.30

340.

0096

5.37

50

(7)

53 ⁄ 8–

12or

5.37

50–

12U

N2A

0.00

205.

3730

5.36

16..

.5.

3189

5.31

210.

0067

895.

2738

2B5.

285

5.30

35.

3209

5.32

970.

0088

5.37

50(7

)3A

0.00

005.

3750

5.36

36..

.5.

3209

5.31

580.

0051

005.

2758

3B5.

2850

5.29

485.

3209

5.32

750.

0066

5.37

50

53 ⁄ 8–

16or

5.37

50–

16U

N2A

0.00

185.

3732

5.36

38..

.5.

3326

5.32

650.

0061

155.

2988

2B5.

307

5.32

15.

3344

5.34

230.

0079

5.37

50(7

)3A

0.00

005.

3750

5.36

56..

.5.

3344

5.32

980.

0046

005.

3006

3B5.

3070

5.31

595.

3344

5.34

040.

0060

5.37

50

51 ⁄ 2–

4or

5.50

00–

4U

N2A

0.00

365.

4964

5.47

26..

.5.

3340

5.32

190.

0121

195.

1987

2B5.

229

5.26

75.

3376

5.35

340.

0158

5.50

003A

0.00

005.

5000

5.47

62..

.5.

3376

5.32

850.

0091

005.

2023

3B5.

2290

5.25

945.

3376

5.34

940.

0118

5.50

00

51 ⁄ 2–

6or

5.50

00–

6U

N2A

0.00

325.

4968

5.47

86..

.5.

3885

5.37

780.

0107

095.

2983

2B5.

320

5.35

05.

3917

5.40

560.

0139

5.50

003A

0.00

005.

5000

5.48

18..

.5.

3917

5.38

370.

0080

005.

3015

3B5.

3200

5.33

965.

3917

5.40

210.

0104

5.50

00

51 ⁄ 2–

8or

5.50

00–

8U

N2A

0.00

305.

4970

5.48

20..

.5.

4158

5.40

590.

0099

165.

3482

2B5.

365

5.39

05.

4188

5.43

170.

0129

5.50

003A

0.00

005.

5000

5.48

50..

.5.

4188

5.41

140.

0074

005.

3512

3B5.

3650

5.37

975.

4188

5.42

850.

0097

5.50

00

(7)

51 ⁄ 2–

12or

5.50

00–

12U

N2A

0.00

205.

4980

5.48

66..

.5.

4439

5.43

710.

0068

095.

3988

2B5.

410

5.42

85.

4459

5.45

480.

0089

5.50

00(7

)3A

0.00

005.

5000

5.48

86..

.5.

4459

5.44

080.

0051

005.

4008

3B5.

4100

5.41

985.

4459

5.45

250.

0066

5.50

00

33




Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(7)

51 ⁄ 2–

16or

5.50

00–

16U

N2A

0.00

185.

4982

5.48

88..

.5.

4576

5.45

150.

0061

355.

4238

2B5.

432

5.44

65.

4594

5.46

740.

0080

5.50

00(7

)3A

0.00

005.

5000

5.49

06..

.5.

4594

5.45

480.

0046

005.

4256

3B5.

4320

5.44

095.

4594

5.46

540.

0060

5.50

00

55 ⁄ 8–

6or

5.62

50–

6U

N2A

0.00

325.

6218

5.60

36..

.5.

5135

5.50

270.

0107

695.

4233

2B5.

445

5.47

55.

5167

5.53

070.

0140

5.62

503A

0.00

005.

6250

5.60

68..

.5.

5167

5.50

860.

0081

005.

4265

3B5.

4450

5.46

465.

5167

5.52

720.

0105

5.62

50

55 ⁄ 8–

8or

5.62

50–

8U

N2A

0.00

305.

6220

5.60

70..

.5.

5408

5.53

080.

0099

765.

4732

2B5.

490

5.51

55.

5438

5.55

680.

0130

5.62

50(7

)3A

0.00

005.

6250

5.61

00..

.5.

5438

5.53

630.

0075

005.

4762

3B5.

4900

5.50

475.

5438

5.55

350.

0097

5.62

50

(7)

55 ⁄ 8–

12or

5.62

50–

12U

N2A

0.00

205.

6230

5.61

16..

.5.

5689

5.56

210.

0068

295.

5238

2B5.

535

5.55

35.

5709

5.57

980.

0089

5.62

50(7

)3A

0.00

005.

6250

5.61

36..

.5.

5709

5.56

580.

0051

005.

5258

3B5.

5350

5.54

485.

5709

5.57

760.

0067

5.62

50

(7)

55 ⁄ 8–

16or

5.62

50–

16U

N2A

0.00

185.

6232

5.61

38..

.5.

5826

5.57

640.

0061

555.

5488

2B5.

557

5.57

15.

5844

5.59

240.

0080

5.62

50(7

)3A

0.00

005.

6250

5.61

56..

.5.

5844

5.57

980.

0046

005.

5506

3B5.

5570

5.56

595.

5844

5.59

040.

0060

5.62

50

53 ⁄ 4–

4or

5.75

00–

4U

N2A

0.00

375.

7463

5.72

25..

.5.

5839

5.57

170.

0122

375.

4486

2B5.

479

5.51

75.

5876

5.60

350.

0159

5.75

003A

0.00

005.

7500

5.72

62..

.5.

5876

5.57

840.

0092

005.

4523

3B5.

4790

5.50

945.

5876

5.59

950.

0119

5.75

00

53 ⁄ 4–

6or

5.75

00–

6U

N2A

0.00

325.

7468

5.72

86..

.5.

6385

5.62

770.

0108

275.

5483

2B5.

570

5.60

05.

6417

5.65

580.

0141

5.75

003A

0.00

005.

7500

5.73

18..

.5.

6417

5.63

360.

0081

005.

5515

3B5.

5700

5.58

965.

6417

5.65

230.

0106

5.75

00

(7)

53 ⁄ 4–

8or

5.75

00–

8U

N2A

0.00

305.

7470

5.73

20..

.5.

6658

5.65

580.

0100

345.

5982

2B5.

615

5.64

05.

6688

5.68

180.

0130

5.75

003A

0.00

005.

7500

5.73

50..

.5.

6688

5.66

130.

0075

005.

6012

3B5.

6150

5.62

975.

6688

5.67

860.

0098

5.75

00

(7)

53 ⁄ 4–

12or

5.75

00–

12U

N2A

0.00

215.

7479

5.73

65..

.5.

6938

5.68

700.

0068

485.

6487

2B5.

660

5.67

85.

6959

5.70

480.

0089

5.75

00(7

)3A

0.00

005.

7500

5.73

86..

.5.

6959

5.69

080.

0051

005.

6508

3B5.

6600

5.66

985.

6959

5.70

260.

0067

5.75

00

(7)

53 ⁄ 4–

6or

5.75

00–

16U

N2A

0.00

195.

7481

5.73

87..

.5.

7075

5.70

130.

0061

745.

6737

2B5.

682

5.69

65.

7094

5.71

740.

0080

5.75

00(7

)3A

0.00

005.

7500

5.74

06..

.5.

7094

5.70

480.

0046

005.

6756

3B5.

6820

5.69

095.

7094

5.71

540.

0060

5.75

00

57 ⁄ 8–

6or

5.87

50–

6U

N2A

0.00

335.

8717

5.85

35..

.5.

7634

5.75

250.

0108

865.

6732

2B5.

695

5.72

55.

7667

5.78

090.

0142

5.87

503A

0.00

005.

8750

5.85

68..

.5.

7667

5.75

850.

0082

005.

6765

3B5.

6950

5.71

465.

7667

5.77

730.

0106

5.87

50

(7)

57 ⁄ 8–

8or

5.87

50–

8U

N2A

0.00

305.

8720

5.85

70..

.5.

7908

5.78

070.

0100

935.

7232

2B5.

740

5.76

55.

7938

5.80

690.

0131

5.87

503A

0.00

005.

8750

5.86

00..

.5.

7938

5.78

620.

0076

005.

7262

3B5.

7400

5.75

475.

7938

5.80

360.

0098

5.87

50

(7)

57 ⁄ 8–

12or

5.87

50–

12U

N2A

0.00

215.

8729

5.86

15..

.5.

8188

5.81

190.

0068

685.

7737

2B5.

785

5.80

35.

8209

5.82

980.

0089

5.87

503A

0.00

005.

8750

5.86

36..

.5.

8209

5.81

570.

0052

005.

7758

3B5.

7850

5.79

485.

8209

5.82

760.

0067

5.87

50

34


Tabl

e2

Lim

its

ofSi

zefo

rSt

anda

rdSe

ries

Thre

ads

(UN

/UN

R)(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(4

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(4)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Min

.M

ax.

Tole

ranc

e[N

ote

(6)]

Dia

met

er,

Thre

ads/

in.

nati

onCl

ass

Allo

wan

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

[Not

e(5

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

57 ⁄ 8–

16or

5.87

50–

16U

N2A

0.00

195.

8731

5.86

37..

.5.

8325

5.82

630.

0061

945.

7987

2B5.

807

5.82

15.

8344

5.84

250.

0081

5.87

50(7

)3A

0.00

005.

8750

5.86

56..

.5.

8344

5.82

980.

0046

005.

8006

3B5.

8070

5.81

595.

8344

5.84

040.

0060

5.87

50

6–

4or

6.00

00–

4U

N2A

0.00

375.

9963

5.97

25..

.5.

8339

5.82

150.

0123

535.

6986

2B5.

729

5.76

75.

8376

5.85

370.

0161

6.00

003A

0.00

006.

0000

5.97

62..

.5.

8376

5.82

830.

0093

005.

7023

3B5.

7290

5.75

945.

8376

5.84

960.

0120

6.00

00

6–

6or

6.00

00–

6U

N2A

0.00

335.

9967

5.97

85..

.5.

8884

5.87

750.

0109

435.

7982

2B5.

820

5.85

05.

8917

5.90

590.

0142

6.00

003A

0.00

006.

0000

5.98

18..

.5.

8917

5.88

350.

0082

005.

8015

3B5.

8200

5.83

965.

8917

5.90

240.

0107

6.00

00

(7)

6–

8or

6.00

00–

8U

N2A

0.00

305.

9970

5.98

20..

.5.

9158

5.90

570.

0101

505.

8482

2B5.

865

5.89

05.

9188

5.93

200.

0132

6.00

00(7

)3A

0.00

006.

0000

5.98

50..

.5.

9188

5.91

120.

0076

005.

8512

3B5.

8650

5.87

975.

9188

5.92

870.

0099

6.00

00

6–

12or

6.00

00–

12U

N2A

0.00

215.

9979

5.98

65..

.5.

9438

5.93

690.

0068

875.

8987

2B5.

910

5.92

85.

9459

5.95

490.

0090

6.00

003A

0.00

006.

0000

5.98

86..

.5.

9459

5.94

070.

0052

005.

9008

3B5.

9100

5.91

985.

9459

5.95

260.

0067

6.00

00

6–

16or

6.00

00–

16U

N2A

0.00

195.

9981

5.98

87..

.5.

9575

5.95

130.

0062

135.

9237

2B5.

932

5.94

65.

9594

5.96

750.

0081

6.00

00(7

)3A

0.00

006.

0000

5.99

06..

.5.

9594

5.95

470.

0047

005.

9256

3B5.

9320

5.94

095.

9594

5.96

550.

0061

6.00

00

GEN

ERA

LN

OTE

:S

erie

sde

sign

atio

nsh

own

indi

cate

sth

eU

Nth

read

form

;ho

wev

er,

the

UN

Rth

read

form

may

besp

ecifi

edby

subs

titu

ting

UN

Rin

plac

eof

UN

inal

lde

sign

atio

nsfo

rex

tern

alus

eon

ly.

NO

TES

:(1

)Th

read

clas

ses

may

beco

mbi

ned.

See

para

.4.

2.(2

)Fo

rCl

ass

2Ath

read

sha

ving

anad

diti

vefin

ish,

the

max

imum

maj

oran

dpi

tch

diam

eter

s,af

ter

coat

ing,

may

equa

lth

eba

sic

size

s,w

hose

valu

esar

eth

esa

me

asm

axim

umva

lues

show

nfo

rCl

ass

3Ain

thes

eco

lum

ns.

See

para

s.4.

1.1

and

4.1.

3.(3

)Fo

run

finis

hed

hot

mat

eria

l,no

tin

clud

ing

stan

dard

fast

ener

sw

ith

rolle

dth

read

s.(4

)S

eepa

ra.

5.2.

1fo

rFu

ncti

onal

Dia

met

er.

(5)

2Api

tch

diam

eter

tole

ranc

e(T

d 2)

islis

ted

and

used

toa

six

plac

ede

cim

alto

calc

ulat

eth

elis

ted

Clas

s1A

/1B

,2B

,3A

/3B

tole

ranc

esan

dCl

ass

1A/2

Aal

low

ance

san

dal

ldi

men

sion

allim

its

that

depe

ndup

onth

em.

(6)

Thes

eva

lues

are

for

refe

renc

eon

ly.

UN

seri

esex

tern

alth

read

max

imum

min

ordi

amet

eris

basi

c(D

1in

para

.11

)fo

rCl

ass

3Aan

dba

sic

min

usal

low

ance

for

Clas

ses

1Aan

d2A

.(7

)O

neor

mor

eof

the

num

bers

liste

din

this

row

have

been

chan

ged

toco

rrec

tfo

rca

lcul

atio

nan

dro

undi

nger

rors

.Th

eor

igin

alnu

mbe

rsfr

ompa

stis

sues

ofB

1.1

are

liste

din

App

endi

xE

and

are

for

refe

renc

eon

ly.

(8)

Form

erly

NF.

Not

are

com

men

ded

stan

dard

size

.To

lera

nces

and

allo

wan

ces

are

base

don

one

diam

eter

leng

thof

enga

gem

ent.

35




4 SCREW THREAD CLASSES

4.1 Thread Classes

Thread classes are distinguished from each other bythe amounts of tolerance and allowance. Classes 1A, 2A,and 3A apply to external threads only, and Classes 1B,2B, and 3B apply to internal threads only. Allowance isspecified only for Classes 1A and 2A and the allowanceis identical for both classes. Tolerance decreases as classnumber increases (e.g., tolerance for Class 3A is less thanthat for Class 2A, which is less than that for Class 1A).

4.1.1 Classes 1A and 1B Threads. Classes 1A (exter-nal) and 1B (internal) threads replaced AmericanNational Class 1 screw threads. These classes providefor applications where a liberal tolerance and an allow-ance are required to permit easy assembly even withslightly nicked threads. These classes are intended forordnance and other special uses. Maximum diametersof Class 1A threads are less than basic by the amountof the allowance (the allowance is identical to that forClass 2A). The allowance is not available for platingor coating; and consequently, in some cases it may benecessary to make special provisions in thread manufac-turing for accommodation of plating or coating. Theminimum diameters of Class 1B threads, whether or notplated or coated, are basic and consequently afford noallowance or clearance for assembly at maximum-mate-rial limits.

4.1.2 Classes 2A and 2B Threads. Classes 2A (exter-nal) and 2B (internal) threads are the most commonlyused thread classes for general applications, includingproduction of bolts, screws, nuts, and similar threadedfasteners.

The maximum diameters of Class 2A uncoatedthreads are less than basic by the amount of the allow-ance. The allowance minimizes galling and seizing inhigh-cycle wrench assembly, or it can be used to accom-modate plated finishes or other coating. However, forthreads with additive finish, the maximum diametersof Class 2A may be exceeded by the amount of theallowance; i.e., the 2A maximum diameters apply to anunplated part or to a part before plating, whereas thebasic diameters apply to a part after plating. The mini-mum diameters of Class 2B threads, whether or notplated or coated, are basic, affording no allowance orclearance in assembly at maximum-material limits.

4.1.3 Classes 3A and 3B Threads. Classes 3A (exter-nal) and 3B (internal) threads provide for applicationswhere closeness of fit and/or accuracy of thread ele-ments are important. The maximum diameters of Class3A threads and the minimum diameters of Class 3Bthreads, whether or not plated or coated, are basic,affording no allowance or clearance for assembly at max-imum-material limits.

36

4.2 Combinations of Classes

The requirements for screw thread fits for specificapplications are predicated on end use and can be metby specifying the proper combinations of thread classesfor the components. For example, a Class 2A externalthread may be used with a Class 1B, 2B, or 3B internalthread.

5 SCREW THREAD ALLOWANCE AND TOLERANCE

5.1 Allowance

Allowance is specified only for Classes 1A and 2Aexternal threads. For Class 1A threads, its purpose is topreclude the possibility of surface-to-surface fit betweenmating parts and it cannot be used to accommodateplating or coating. For Class 2A threads, the allowancemay be used to accommodate plating or coating. Allow-ance for Classes 1A and 2A is identical and is basedon Class 2A pitch diameter tolerance for the respectiveseries standard length of engagement and is applicablefor all lengths of engagement.

Formulas for allowance are given in para. 5.8.1(a).Applications of allowances to the basic thread form

are shown in Fig. 2.

EXAMPLE: 2.0625-12-UNS-2AFrom para. 5.8.1(a): Allowance, es p 0.300 Td2(2A).From para. 5.2, example (1): Td2(2A) p 0.006070.Therefore, es p 0.300 � 0.006070 p 0.001821, or 0.0018 in. when

rounded.

5.2 Pitch Diameter Tolerance, All ClassesNOTE: Refer to Table 1 for the standard series of diameter-pitchcombinations. Allowances and tolerances for standard seriesthreads are applied in Table 2. All other diameter-pitch combina-tions are considered nonstandard. Allowances and tolerances fornonstandard threads must be calculated using the appropriateformulas contained in this Standard.

The pitch diameter tolerances specified in Table 2 forall classes of the UNC and UNF series are based on alength of engagement equal to the basic major (nominal)diameter and are applicable for lengths of engagementfrom 5 pitches to up to 1.5 diameters. For the 4-UN,6-UN, and 8-UN series, the pitch diameter tolerancesspecified for Classes 2A, 2B, 3A, and 3B are based on alength of engagement equal to the basic major (nominal)diameter and are applicable for lengths of engagementup to 1.5 diameters.

The pitch diameter tolerances specified in Table 2 forall classes of the UNEF, 12-UN, 16-UN, 20-UN, 28-UN,and 32-UN series are based on a length of engagementof 9 pitches and are applicable for lengths of engagementfrom 5 to 15 pitches.

The pitch diameter tolerances specified in Table D-1of Nonmandatory Appendix D for all classes of the UNSseries are based on a length of engagement of 9 pitchesand are applicable for lengths of engagement from 5 to15 pitches.


Formulas for pitch diameter tolerance are given inparas. 5.8.1(c) and 5.8.2(b).

Applications of tolerances to the thread form areshown in Figs. 2 and 3.

For special threads, tolerances and allowances shallbe computed from the formulas in paras. 5.8.1 and 5.8.2.If the length of engagement is between 5 and 15 pitchesor is unknown, use 9 pitches in the applicable formulas.For all other lengths of engagement, use the knownvalues.

EXAMPLES:

(1) 2.0625-12-UNS-2A (length of engagement not specified)

Td2 p 0.0015 3�D+ 0.0015�LE+ 0.015 3�P 2

Td2p 0.0015 3�2.0625+ 0.0015�9/12 + 0.015 3�0.08333333 2

Td2 p 0.001909 + 0.001299 + 0.002862

Td2 p 0.006070

(2) 2.0625-12-UNS-SE2A (18 pitches length of engagement)

Td2 p 0.0015 3�D+ 0.0015�LE + 0.015 3�P 2

Td2 p 0.0015 3�2.0625+ 0.0015�1.500 + 0.015 3�0.08333333 2

Td2 p 0.001909 + 0.001837 + 0.002862

Td2 p 0.006608

5.2.1 Functional Diameter. Functional diameter sizeincludes the effects of all variations in pitch diameter,thread form, and profile. The variations in the individualthread characteristics, such as flank angle, lead, taper,and roundness, on a given thread cause the measure-ments of the pitch diameter and functional diameterto vary from one another on most threads. The pitchdiameter and functional diameter on a given threadare equal to one another only when the thread form isperfect.

When required to inspect/evaluate either the pitchdiameter and/or the functional diameter for threadacceptance (see ASME B1.3), use the same limits of sizefor the appropriate thread size and class.

5.3 Special Lengths of Engagement, LE

For special applications, the required length ofengagement might be the determining factor in theproper selection of thread tolerances. When design con-siderations require nonstandard pitches or extreme con-ditions of engagement not covered by the tables, thetolerances may be adjusted using the formulas. It isparticularly important that changes in tolerance benoted by the user for external threads designated Class3A when using longer than standard lengths ofengagement.

5.3.1 Long LE Using Gage Length LG Equal to LE(a) High-Strength Materials Using Standard Pitch Diame-

ter Tolerances. For applications of long length of engage-ment of mating parts involving very high-strength

37

materials, increases in tolerances based on standardlength of engagement may be detrimental. In these cases,the tolerances based on the standard length of engage-ment may be applied to increased length of engagementthreads. This requires the GO thread gages to have aspecial length equal to the length of engagement.

(b) Standard Bolt, Added Allowance in Tapped Hole, LEIncreases. In some cases where greater than standardlength of engagement is required, it is desirable to usestandard externally threaded parts with tolerancesbased on standard length of engagement. For example,in the case of a standard bolt assembled into a tappedhole in aluminum, the designation of the bolt threadwill conform to that of a thread for a standard lengthof engagement.

To ensure proper assembly, the tapped hole threadinto which the bolt is assembled must not interfere withthe bolt thread. This could happen if no special provi-sions were made in the tapped hole thread due to thecumulative effect of lead variation on the bolt thread,inasmuch as the increased length of engagement exceedsthe thickness of the GO thread gage used for acceptanceof the bolt thread. To avoid this condition, an allowanceshould be provided in the tapped hole, the amount ofwhich should be the diameter equivalent of the cumula-tive lead variation for the increased length of engage-ment, which is one-half the pitch diameter toleranceof the bolt thread allowed for the standard length ofengagement. This requires the GO thread and GO plaingages to have a special length equal to the length ofengagement.

EXAMPLE: 0.5000-13UNC-SE2B; LEp1 in. (2 diameters); assem-bled with standard bolt thread.

Add allowance EIp 1⁄2Td2 for standard bolt thread. From Table3, column 5, 1⁄2Td2 (standard) p 0.0025. Therefore, the thread isredesignated to indicate a nonstandard internal thread with theallowance of 0.0025 added to the basic size of 0.5000. New designa-tion is 0.5025-13UNS-SE2B. Allowance is also added to the standardminor diameter size limits and to the adjusted pitch diameter sizelimits. See para. 6.6.1.

(c) Standard Internal Thread, Added Allowance on Exter-nal Thread, es, Increases. In some cases where greater thanstandard length of engagement is required, it is desirableto use standard internally threaded parts with tolerancesbased on standard length of engagement. In these casesan allowance should be added to the mating externalthread.

EXAMPLE: 0.3750-24UNF-SE2A; LEp0.88 in. (2.35 diameters);assembled with standard internal thread.

Add allowance, equal to 1⁄2TD2 for standard internal thread. FromTable 3, column 8, 1⁄2TD2 (standard)p0.00245, which is rounded to0.0025. Therefore, the thread is redesignated to indicate a nonstan-dard external thread with the allowance of 0.0025 subtracted fromthe basic size of 0.3750. New designation is 0.3725-24UNS-SE2A.The added allowance is also subtracted from the standard majordiameter size limits and from the adjusted pitch diameter sizelimits. See para. 6.6.1.




Table 3 Allowable Variations in Lead and Equivalent Change in Functional DiameterGENERAL NOTE: See paras. 9.1.3 through 9.1.6 for applicability.

External Internal

Allowable Equivalent Change Allowable Equivalent ChangeNominal Size Variation in Functional Variation in Functional

and Series in Lead, Diameter, in., in Lead, Diameter, in.,Threads/in. Designation Class in. (±) 1⁄2Td2 (+) Class in. (±) 1⁄2TD2 (−)

1 2 3 4 5 6 7 8

0 – 80 or 0.060 – 80 UNF 2A 0.00052 0.00090 2B 0.00066 0.001153A 0.00038 0.00065 3B 0.00048 0.00085

1 – 64 or 0.073 – 64 UNC 2A 0.00058 0.00100 2B 0.00075 0.001303A 0.00043 0.00075 3B 0.00055 0.00095

1 – 72 or 0.073 – 72 UNF 2A 0.00055 0.00095 2B 0.00072 0.001253A 0.00040 0.00070 3B 0.00055 0.00095

2 – 56 or 0.086 – 56 UNC 2A 0.00061 0.00105 2B 0.00081 0.001403A 0.00046 0.00080 3B 0.00061 0.00105

2 – 64 or 0.086 – 64 UNF 2A 0.00058 0.00100 2B 0.00078 0.001353A 0.00043 0.00075 3B 0.00058 0.00100

3 – 48 or 0.099 – 48 UNC 2A 0.00066 0.00115 2B 0.00087 0.001503A 0.00049 0.00085 3B 0.00064 0.00110

3 – 56 or 0.099 – 56 UNF 2A 0.00064 0.00110 2B 0.00081 0.001403A 0.00046 0.00080 3B 0.00061 0.00105

4 – 40 or 0.112 – 40 UNC 2A 0.00072 0.00125 2B 0.00095 0.001653A 0.00055 0.00095 3B 0.00069 0.00120

4 – 48 or 0.112 – 48 UNF 2A 0.00069 0.00120 2B 0.00089 0.001553A 0.00052 0.00090 3B 0.00066 0.00115

5 – 40 or 0.125 – 40 UNC 2A 0.00075 0.00130 2B 0.00095 0.001653A 0.00055 0.00095 3B 0.00072 0.00125

5 – 44 or 0.125 – 44 UNF 2A 0.00072 0.00125 2B 0.00092 0.001603A 0.00055 0.00095 3B 0.00069 0.00120

6 – 32 or 0.138 – 32 UNC 2A 0.00081 0.00140 2B 0.00107 0.001853A 0.00061 0.00105 3B 0.00078 0.00135

6 – 40 or 0.138 – 40 UNF 2A 0.00075 0.00130 2B 0.00098 0.001703A 0.00058 0.00100 3B 0.00072 0.00125

8 – 32 or 0.164 – 32 UNC 2A 0.00084 0.00145 2B 0.00110 0.001903A 0.00064 0.00110 3B 0.00081 0.00140

8 – 36 or 0.164 – 36 UNF 2A 0.00081 0.00140 2B 0.00104 0.001803A 0.00061 0.00105 3B 0.00078 0.00135

10 – 24 or 0.190 – 24 UNC 2A 0.00095 0.00165 2B 0.00124 0.002153A 0.00072 0.00125 3B 0.00092 0.00160

10 – 32 or 0.190 – 32 UNF 2A 0.00087 0.00150 2B 0.00113 0.001953A 0.00066 0.00115 3B 0.00084 0.00145

12 – 24 or 0.216 – 24 UNC 2A 0.00098 0.00170 2B 0.00127 0.002203A 0.00075 0.00130 3B 0.00095 0.00165

12 – 28 or 0.216 – 28 UNF 2A 0.00092 0.00160 2B 0.00121 0.002103A 0.00069 0.00120 3B 0.00089 0.00155

12 – 32 or 0.216 – 32 UNEF 2A 0.00089 0.00155 2B 0.00118 0.002053A 0.00069 0.00120 3B 0.00089 0.00155

1⁄4 – 20 or 0.250 – 20 UNC 1A 0.00162 0.00280 1B 0.00211 0.003652A 0.00107 0.00185 2B 0.00141 0.002453A 0.00081 0.00140 3B 0.00104 0.00180

38


Table 3 Allowable Variations in Lead and Equivalent Change in Functional Diameter (Cont’d)GENERAL NOTE: See paras. 9.1.3 through 9.1.6 for applicability.

External Internal


and Series in Lead, Diameter, in., in Lead, Diameter, in.Threads/in. Designation Class in. (±) 1⁄2Td2 (+) Class in. (±) 1⁄2TD2 (−)

1 2 3 4 5 6 7 8

1⁄4 – 28 or 0.250 – 28 UNF 1A 0.00144 0.00250 1B 0.00188 0.003252A 0.00095 0.00165 2B 0.00124 0.002153A 0.00072 0.00125 3B 0.00092 0.00160

1⁄4 – 32 or 0.250 – 32 UNEF 2A 0.00092 0.00160 2B 0.00121 0.002103A 0.00069 0.00120 3B 0.00089 0.00155

5⁄16 – 18 or 0.3125 – 18 UNC 1A 0.00176 0.00305 1B 0.00223 0.003952A 0.00115 0.00200 2B 0.00153 0.002653A 0.00087 0.00150 3B 0.00113 0.00195

5⁄16 – 20 or 0.3125 – 20 UN 2A 0.00115 0.00200 2B 0.00150 0.002603A 0.00087 0.00150 3B 0.00113 0.00195

5⁄16 – 24 or 0.3125 – 24 UNF 1A 0.00159 0.00275 1B 0.00205 0.003552A 0.00107 0.00185 2B 0.00139 0.002403A 0.00078 0.00135 3B 0.00104 0.00180

5⁄16 – 28 or 0.3125 – 28 UN 2A 0.00098 0.00170 2B 0.00127 0.002203A 0.00075 0.00130 3B 0.00095 0.00165

5⁄16 – 32 or 0.3125 – 32 UNEF 2A 0.00092 0.00160 2B 0.00121 0.002103A 0.00069 0.00120 3B 0.00089 0.00155

3⁄8 – 16 or 0.375 – 16 UNC 1A 0.00188 0.00325 1B 0.00245 0.004252A 0.00127 0.00220 2B 0.00165 0.002853A 0.00095 0.00165 3B 0.00124 0.00215

3⁄8 – 20 or 0.375 – 20 UN 2A 0.00118 0.00205 2B 0.00156 0.002703A 0.00089 0.00155 3B 0.00115 0.00200

3⁄8 – 24 or 0.375 – 24 UNF 1A 0.00165 0.00285 1B 0.00214 0.003702A 0.00110 0.00190 2B 0.00141 0.002453A 0.00084 0.00145 3B 0.00107 0.00185

3⁄8 – 28 or 0.375 – 28 UN 2A 0.00104 0.00180 2B 0.00133 0.002303A 0.00078 0.00135 3B 0.00101 0.00175

3⁄8 – 32 or 0.375 – 32 UNEF 2A 0.00098 0.00170 2B 0.00127 0.002203A 0.00072 0.00125 3B 0.00095 0.00165

7⁄16 – 14 or 0.4375 – 14 UNC 1A 0.00205 0.00355 1B 0.00266 0.004602A 0.00136 0.00235 2B 0.00176 0.003053A 0.00101 0.00175 3B 0.00133 0.00230

7⁄16 – 16 or 0.4375 – 16 UN 2A 0.00133 0.00230 2B 0.00170 0.002953A 0.00098 0.00170 3B 0.00130 0.00225

7⁄16 – 20 or 0.4375 – 20 UNF 1A 0.00182 0.00315 1B 0.00234 0.004052A 0.00121 0.00210 2B 0.00156 0.002703A 0.00089 0.00155 3B 0.00118 0.00205

7⁄16 – 28 or 0.4375 – 28 UNEF 2A 0.00104 0.00180 2B 0.00133 0.002303A 0.00078 0.00135 3B 0.00101 0.00175

7⁄16 – 32 or 0.4375 – 32 UN 2A 0.00098 0.00170 2B 0.00127 0.002203A 0.00072 0.00125 3B 0.00095 0.00165

1⁄2 – 13 or 0.500 – 13 UNC 1A 0.00214 0.00370 1B 0.00280 0.004852A 0.00144 0.00250 2B 0.00188 0.003253A 0.00107 0.00185 3B 0.00139 0.00240

39





External Internal


and Series in Lead, Diameter, in., in Lead, in. Diameter, in.Threads/in. Designation Class in. (±) 1⁄2Td2 (+) Class (±) 1⁄2TD2 (−)

1 2 3 4 5 6 7 8

1⁄2 – 16 or 0.500 – 16 UN 2A 0.00136 0.00235 2B 0.00176 0.003053A 0.00101 0.00175 3B 0.00133 0.00230

1⁄2 – 20 or 0.500 – 20 UNF 1A 0.00185 0.00320 1B 0.00242 0.004202A 0.00124 0.00215 2B 0.00162 0.002803A 0.00092 0.00160 3B 0.00121 0.00210

1⁄2 – 28 or 0.500 – 28 UNEF 2A 0.00107 0.00185 2B 0.00139 0.002403A 0.00081 0.00140 3B 0.00104 0.00180

1⁄2 – 32 or 0.500 – 32 UN 2A 0.00101 0.00175 2B 0.00130 0.002253A 0.00075 0.00130 3B 0.00098 0.00170

9⁄16 – 12 or 0.5625 – 12 UNC 1A 0.00225 0.00390 1B 0.00294 0.005102A 0.00150 0.00260 2B 0.00196 0.003403A 0.00113 0.00195 3B 0.00147 0.00255

9⁄16 – 16 or 0.5625 – 16 UN 2A 0.00136 0.00235 2B 0.00176 0.003053A 0.00101 0.00175 3B 0.00133 0.00230

9⁄16 – 18 or 0.5625 – 18 UNF 1A 0.00196 0.00340 1B 0.00257 0.004452A 0.00130 0.00225 2B 0.00170 0.002953A 0.00098 0.00170 3B 0.00127 0.00220

9⁄16 – 20 or 0.5625 – 20 UN 2A 0.00121 0.00210 2B 0.00159 0.002753A 0.00092 0.00160 3B 0.00118 0.00205

9⁄16 – 24 or 0.5625 – 24 UNEF 2A 0.00113 0.00195 2B 0.00147 0.002553A 0.00084 0.00145 3B 0.00110 0.00190

9⁄16 – 28 or 0.5625 – 28 UN 2A 0.00107 0.00185 2B 0.00139 0.002403A 0.00081 0.00140 3B 0.00104 0.00180

9⁄16 – 32 or 0.5625 – 32 UN 2A 0.00101 0.00175 2B 0.00130 0.002253A 0.00075 0.00130 3B 0.00098 0.00170

5⁄8 – 11 or 0.625 – 11 UNC 1A 0.00240 0.00415 1B 0.00309 0.005352A 0.00159 0.00275 2B 0.00208 0.003603A 0.00118 0.00205 3B 0.00156 0.00270

5⁄8 – 12 or 0.625 – 12 UN 2A 0.00156 0.00270 2B 0.00205 0.003553A 0.00118 0.00205 3B 0.00153 0.00265

5⁄8 – 16 or 0.625 – 16 UN 2A 0.00139 0.00240 2B 0.00179 0.003103A 0.00104 0.00180 3B 0.00133 0.00230

5⁄8 – 18 or 0.625 – 18 UNF 1A 0.00202 0.00350 1B 0.00263 0.004552A 0.00136 0.00235 2B 0.00173 0.003003A 0.00101 0.00175 3B 0.00130 0.00255

5⁄8 – 20 or 0.625 – 20 UN 2A 0.00124 0.00215 2B 0.00162 0.002803A 0.00092 0.00160 3B 0.00121 0.00210

5⁄8 – 24 or 0.625 – 24 UNEF 2A 0.00115 0.00200 2B 0.00150 0.002603A 0.00087 0.00150 3B 0.00113 0.00195

5⁄8 – 28 or 0.625 – 28 UN 2A 0.00110 0.00190 2B 0.00141 0.002453A 0.00081 0.00140 3B 0.00107 0.00185

5⁄8 – 32 or 0.625 – 32 UN 2A 0.00104 0.00180 2B 0.00133 0.002303A 0.00078 0.00135 3B 0.00101 0.00175

11⁄16 – 12 or 0.6875 – 12 UN 2A 0.00156 0.00270 2B 0.00205 0.003553A 0.00118 0.00205 3B 0.00153 0.00265

40



External Internal



1 2 3 4 5 6 7 8

11⁄16 – 16 or 0.6875 – 16 UN 2A 0.00139 0.00240 2B 0.00179 0.003103A 0.00104 0.00130 3B 0.00133 0.00230

11⁄16 – 20 or 0.6875 – 20 UN 2A 0.00124 0.00215 2B 0.00162 0.002803A 0.00092 0.00160 3B 0.00121 0.00210

11⁄16 – 24 or 0.6875 – 24 UNEF 2A 0.00115 0.00200 2B 0.00150 0.002603A 0.00087 0.00150 3B 0.00113 0.00195

11⁄16 – 28 or 0.6875 – 28 UN 2A 0.00110 0.00190 2B 0.00141 0.002453A 0.00081 0.00140 3B 0.00107 0.00185

11⁄16 – 32 or 0.6875 – 32 UN 2A 0.00104 0.00180 2B 0.00133 0.002303A 0.00078 0.00135 3B 0.00101 0.00175

3⁄4 – 10 or 0.750 – 10 UNC 1A 0.00254 0.00440 1B 0.00332 0.005752A 0.00170 0.00295 2B 0.00222 0.003853A 0.00127 0.00220 3B 0.00165 0.00285

3⁄4 – 12 or 0.750 – 12 UN 2A 0.00159 0.00275 2B 0.00208 0.003603A 0.00118 0.00205 3B 0.00156 0.00270

3⁄4 – 16 or 0.750 – 16 UNF 1A 0.00217 0.00375 1B 0.00283 0.004902A 0.00144 0.00250 2B 0.00188 0.003253A 0.00110 0.00190 3B 0.00141 0.00245

3⁄4 – 20 or 0.750 – 20 UNEF 2A 0.00127 0.00220 2B 0.00165 0.002853A 0.00095 0.00165 3B 0.00124 0.00215

3⁄4 – 28 or 0.750 – 28 UN 2A 0.00110 0.00190 2B 0.00144 0.002503A 0.00084 0.00145 3B 0.00107 0.00185

3⁄4 – 32 or 0.750 – 32 UN 2A 0.00104 0.00180 2B 0.00136 0.002353A 0.00078 0.00135 3B 0.00104 0.00180

13⁄16 – 12 or 0.8125 – 12 UN 2A 0.00159 0.00275 2B 0.00208 0.003603A 0.00118 0.00205 3B 0.00156 0.00270

13⁄16 – 16 or 0.8125 – 16 UN 2A 0.00141 0.00245 2B 0.00182 0.003153A 0.00104 0.00180 3B 0.00136 0.00235

13⁄16 – 20 or 0.8125 – 20 UNEF 2A 0.00127 0.00220 2B 0.00165 0.002853A 0.00095 0.00165 3B 0.00124 0.00215

13⁄16 – 28 or 0.8125 – 28 UN 2A 0.00110 0.00190 2B 0.00144 0.002503A 0.00084 0.00145 3B 0.00107 0.00185

13⁄16 – 32 or 0.8125 – 32 UN 2A 0.00104 0.00180 2B 0.00136 0.002353A 0.00078 0.00135 3B 0.00104 0.00180

7⁄8 – 9 or 0.875 – 9 UNC 1A 0.00274 0.00475 1B 0.00355 0.006152A 0.00182 0.00315 2B 0.00237 0.004103A 0.00136 0.00235 3B 0.00176 0.00305

7⁄8 – 12 or 0.875 – 12 UN 2A 0.00159 0.00275 2B 0.00208 0.003603A 0.00118 0.00205 3B 0.00156 0.00270

7⁄8 – 14 or 0.875 – 14 UNF 1A 0.00234 0.00405 1B 0.00306 0.005302A 0.00156 0.00270 2B 0.00202 0.003503A 0.00118 0.00205 3B 0.00153 0.00265

7⁄8 – 16 or 0.875 – 16 UN 2A 0.00141 0.00245 2B 0.00182 0.003153A 0.00104 0.00180 3B 0.00136 0.00235

41





External Internal



1 2 3 4 5 6 7 8

7⁄8 – 20 or 0.875 – 20 UNEF 2A 0.00127 0.00220 2B 0.00165 0.002853A 0.00095 0.00165 3B 0.00124 0.00215

7⁄8 – 28 or 0.875 – 28 UN 2A 0.00110 0.00190 2B 0.00144 0.002503A 0.00084 0.00145 3B 0.00107 0.00185

7⁄8 – 32 or 0.875 – 32 UN 2A 0.00104 0.00180 2B 0.00136 0.002353A 0.00078 0.00135 3B 0.00104 0.00180

15⁄16 – 12 or 0.9375 – 12 UN 2A 0.00165 0.00255 2B 0.00214 0.003703A 0.00121 0.00210 3B 0.00159 0.00275

15⁄16 – 16 or 0.9375 – 16 UN 2A 0.00144 0.00250 2B 0.00188 0.003253A 0.00107 0.00185 3B 0.00141 0.00245

15⁄16 – 20 or 0.9375 – 20 UNEF 2A 0.00130 0.00225 2B 0.00170 0.002953A 0.00098 0.00170 3B 0.00127 0.00220

15⁄16 – 28 or 0.9375 – 28 UN 2A 0.00115 0.00200 2B 0.00150 0.002603A 0.00087 0.00150 3B 0.00113 0.00195

15⁄16 – 32 or 0.9375 – 32 UN 2A 0.00110 0.00190 2B 0.00141 0.002453A 0.00081 0.00140 3B 0.00107 0.00185

1 – 8 or 1.000 – 8 UNC 1A 0.00292 0.00505 1B 0.00381 0.006602A 0.00196 0.00340 2B 0.00254 0.004403A 0.00147 0.00255 3B 0.00191 0.00330

1 – 12 or 1.000 – 12 UNF 1A 0.00254 0.00440 1B 0.00329 0.005702A 0.00170 0.00295 2B 0.00219 0.003803A 0.00127 0.00220 3B 0.00165 0.00285

1 – 14 or 1.000 – 14 UNS 1A 0.00242 0.00420 1B 0.00315 0.005452A 0.00162 0.00280 2B 0.00211 0.003653A 0.00121 0.00210 3B 0.00156 0.00270

1 – 16 or 1.000 – 16 UN 2A 0.00144 0.00250 2B 0.00188 0.003253A 0.00107 0.00185 3B 0.00141 0.00245

1 – 20 or 1.000 – 20 UNEF 2A 0.00130 0.00225 2B 0.00170 0.002953A 0.00098 0.00170 3B 0.00127 0.00220

1 – 28 or 1.000 – 28 UN 2A 0.00115 0.00200 2B 0.00150 0.002603A 0.00087 0.00150 3B 0.00113 0.00195

1 – 32 or 1.000 – 32 UN 2A 0.00110 0.00190 2B 0.00141 0.002453A 0.00081 0.00140 3B 0.00107 0.00185

11⁄16 – 8 or 1.0625 – 8 UN 2A 0.00196 0.00340 2B 0.00257 0.004453A 0.00147 0.00255 3B 0.00193 0.00335

11⁄16 – 12 or 1.0625 – 12 UN 2A 0.00165 0.00285 2B 0.00214 0.003703A 0.00121 0.00210 3B 0.00159 0.00275

11⁄16 – 16 or 1.0625 – 16 UN 2A 0.00144 0.00250 2B 0.00188 0.003253A 0.00107 0.00185 3B 0.00141 0.00245

11⁄16 – 18 or 1.0625 – 18 UNEF 2A 0.00136 0.00235 2B 0.00179 0.003103A 0.00104 0.00180 3B 0.00133 0.00230

11⁄16 – 20 or 1.0625 – 20 UN 2A 0.00130 0.00225 2B 0.00170 0.002953A 0.00098 0.00170 3B 0.00127 0.00220

42



External Internal



1 2 3 4 5 6 7 8

11⁄16 – 28 or 1.0625 – 28 UN 2A 0.00115 0.00200 2B 0.00150 0.002603A 0.00087 0.00150 3B 0.00113 0.00195

11⁄8 – 7 or 1.125 – 7 UNC 1A 0.00315 0.00545 1B 0.00407 0.007052A 0.00208 0.00360 2B 0.00271 0.004703A 0.00156 0.00270 3B 0.00205 0.00355

11⁄8 – 8 or 1.125 – 8 UN 2A 0.00199 0.00345 2B 0.00260 0.004503A 0.00150 0.00260 3B 0.00193 0.00335

11⁄8 – 12 or 1.125 – 12 UNF 1A 0.00260 0.00450 1B 0.00338 0.005852A 0.00173 0.00300 2B 0.00225 0.003903A 0.00130 0.00225 3B 0.00170 0.00295

11⁄8 – 16 or 1.125 – 16 UN 2A 0.00144 0.00250 2B 0.00188 0.003253A 0.00107 0.00185 3B 0.00141 0.00245

11⁄8 – 18 or 1.125 – 18 UNEF 2A 0.00136 0.00235 2B 0.00179 0.003103A 0.00104 0.00180 3B 0.00133 0.00230

11⁄8 – 20 or 1.125 – 20 UN 2A 0.00130 0.00225 2B 0.00170 0.002953A 0.00098 0.00170 3B 0.00127 0.00220

11⁄8 – 28 or 1.125 – 28 UN 2A 0.00115 0.00200 2B 0.00150 0.002603A 0.00087 0.00150 3B 0.00113 0.00195

13⁄16 – 8 or 1.1875 – 8 UN 2A 0.00202 0.00350 2B 0.00263 0.004553A 0.00150 0.00260 3B 0.00196 0.00340

13⁄16 – 12 or 1.1875 – 12 UN 2A 0.00167 0.00290 2B 0.00217 0.003753A 0.00124 0.00215 3B 0.00162 0.00280

13⁄16 – 16 or 1.1875 – 16 UN 2A 0.00147 0.00255 2B 0.00191 0.003303A 0.00110 0.00190 3B 0.00144 0.00250

13⁄16 – 18 or 1.1875 – 18 UNEF 2A 0.00141 0.00245 2B 0.00182 0.003153A 0.00104 0.00180 3B 0.00136 0.00235

13⁄16 – 20 or 1.1875 – 20 UN 2A 0.00136 0.00235 2B 0.00176 0.003053A 0.00101 0.00175 3B 0.00130 0.00225

13⁄16 – 28 or 1.1875 – 28 UN 2A 0.00118 0.00205 2B 0.00153 0.002653A 0.00089 0.00155 3B 0.00115 0.00200

11⁄4 – 7 or 1.250 – 7 UNC 1A 0.00320 0.00555 1B 0.00416 0.007202A 0.00214 0.00370 2B 0.00277 0.004803A 0.00159 0.00275 3B 0.00208 0.00360

11⁄4 – 8 or 1.250 – 8 UN 2A 0.00202 0.00350 2B 0.00266 0.004603A 0.00153 0.00265 3B 0.00199 0.00345

11⁄4 – 12 or 1.250 – 12 UNF 1A 0.00266 0.00460 1B 0.00346 0.006002A 0.00179 0.00310 2B 0.00231 0.004003A 0.00133 0.00230 3B 0.00173 0.00300

11⁄4 – 16 or 1.250 – 16 UN 2A 0.00147 0.00255 2B 0.00191 0.003303A 0.00100 0.00190 3B 0.00144 0.00250

11⁄4 – 18 or 1.250 – 18 UNEF 2A 0.00141 0.00245 2B 0.00182 0.003153A 0.00104 0.00180 3B 0.00136 0.00235

11⁄4 – 20 or 1.250 – 20 UN 2A 0.00136 0.00235 2B 0.00176 0.003053A 0.00101 0.00175 3B 0.00130 0.00225

43





External Internal



1 2 3 4 5 6 7 8

11⁄4 – 28 or 1.250 – 28 UN 2A 0.00118 0.00205 2B 0.00153 0.002653A 0.00089 0.00155 3B 0.00115 0.00200

15⁄16 – 8 or 1.3125 – 8 UN 2A 0.00205 0.00355 2B 0.00266 0.004603A 0.00153 0.00265 3B 0.00199 0.00345

15⁄16 – 12 or 1.3125 – 12 UN 2A 0.00167 0.00290 2B 0.00217 0.003753A 0.00124 0.00215 3B 0.00162 0.00280

15⁄16 – 16 or 1.3125 – 16 UN 2A 0.00147 0.00255 2B 0.00191 0.003303A 0.00110 0.00190 3B 0.00144 0.00250

15⁄16 – 18 or 1.3125 – 18 UNEF 2A 0.00141 0.00245 2B 0.00182 0.003153A 0.00104 0.00180 3B 0.00136 0.00235

15⁄16 – 20 or 1.3125 – 20 UN 2A 0.00136 0.00235 2B 0.00176 0.003053A 0.00101 0.00175 3B 0.00130 0.00225

15⁄16 – 28 or 1.3125 – 28 UN 2A 0.00118 0.00205 2B 0.00153 0.002653A 0.00089 0.00155 3B 0.00115 0.00200

13⁄8 – 6 or 1.375 – 6 UNC 1A 0.00346 0.00600 1B 0.00447 0.007752A 0.00231 0.00400 2B 0.00300 0.005203A 0.00173 0.00300 3B 0.00225 0.00390

13⁄8 – 8 or 1.375 – 8 UN 2A 0.00208 0.00360 2B 0.00268 0.004653A 0.00156 0.00270 3B 0.00202 0.00350

13⁄8 – 12 or 1.375 – 12 UNF 1A 0.00271 0.00470 1B 0.00355 0.006152A 0.00182 0.00315 2B 0.00237 0.004103A 0.00136 0.00235 3B 0.00176 0.00305

13⁄8 – 16 or 1.375 – 16 UN 2A 0.00147 0.00255 2B 0.00191 0.003303A 0.00110 0.00190 3B 0.00144 0.00250

13⁄8 – 18 or 1.375 – 18 UNEF 2A 0.00141 0.00245 2B 0.00182 0.003153A 0.00104 0.00180 3B 0.00136 0.00235

13⁄8 – 20 or 1.375 – 20 UN 2A 0.00136 0.00235 2B 0.00176 0.003053A 0.00101 0.00175 3B 0.00130 0.00225

13⁄8 – 28 or 1.375 – 28 UN 2A 0.00118 0.00205 2B 0.00153 0.002653A 0.00089 0.00155 3B 0.00115 0.00200

17⁄16 – 6 or 1.4375 – 6 UN 2A 0.00231 0.00400 2B 0.00300 0.005203A 0.00173 0.00300 3B 0.00225 0.00390

17⁄16 – 8 or 1.4375 – 8 UN 2A 0.00208 0.00360 2B 0.00271 0.004703A 0.00156 0.00270 3B 0.00205 0.00355

17⁄16 – 12 or 1.4375 – 12 UN 2A 0.00170 0.00295 2B 0.00219 0.003803A 0.00127 0.00220 3B 0.00165 0.00285

17⁄16 – 16 or 1.4375 – 16 UN 2A 0.00150 0.00260 2B 0.00196 0.003403A 0.00113 0.00195 3B 0.00147 0.00255

17⁄16 – 18 or 1.4375 – 18 UNEF 2A 0.00144 0.00250 2B 0.00188 0.003253A 0.00107 0.00185 3B 0.00139 0.00240

17⁄16 – 20 or 1.4375 – 20 UN 2A 0.00139 0.00240 2B 0.00179 0.003103A 0.00104 0.00180 3B 0.00133 0.00230

17⁄16 – 28 or 1.4375 – 28 UN 2A 0.00121 0.00210 2B 0.00159 0.002753A 0.00089 0.00155 3B 0.00118 0.00205

44



External Internal



1 2 3 4 5 6 7 8

11⁄2 – 6 or 1.500 – 6 UNC 1A 0.00349 0.00605 1B 0.00456 0.007902A 0.00234 0.00405 2B 0.00303 0.005253A 0.00176 0.00305 3B 0.00228 0.00305

11⁄2 – 8 or 1.500 – 8 UN 2A 0.00211 0.00365 2B 0.00274 0.004753A 0.00159 0.00275 3B 0.00205 0.00355

11⁄2 – 12 or 1.500 – 12 UNF 1A 0.00277 0.00480 1B 0.00361 0.006252A 0.00185 0.00320 2B 0.00240 0.004153A 0.00139 0.00240 3B 0.00182 0.00315

11⁄2 – 16 or 1.500 – 16 UN 2A 0.00150 0.00260 2B 0.00196 0.003403A 0.00113 0.00195 3B 0.00147 0.00255

11⁄2 – 18 or 1.500 – 18 UNEF 2A 0.00144 0.00250 2B 0.00188 0.003253A 0.00107 0.00185 3B 0.00139 0.00240

11⁄2 – 20 or 1.500 – 20 UN 2A 0.00139 0.00240 2B 0.00179 0.003103A 0.00104 0.00180 3B 0.00133 0.00230

11⁄2 – 28 or 1.500 – 28 UN 2A 0.00121 0.00210 2B 0.00159 0.002753A 0.00089 0.00155 3B 0.00118 0.00205

19⁄16 – 6 or 1.5625 – 6 UN 2A 0.00237 0.00410 2B 0.00306 0.005303A 0.00176 0.00305 3B 0.00231 0.00400

19⁄16 – 8 or 1.5625 – 8 UN 2A 0.00214 0.00370 2B 0.00277 0.004803A 0.00159 0.00275 3B 0.00208 0.00360

19⁄16 – 12 or 1.5625 – 12 UN 2A 0.00170 0.00295 2B 0.00219 0.003803A 0.00127 0.00220 3B 0.00165 0.00285

19⁄16 – 16 or 1.5625 – 16 UN 2A 0.00150 0.00260 2B 0.00196 0.003403A 0.00113 0.00195 3B 0.00147 0.00255

19⁄16 – 18 or 1.5625 – 18 UNEF 2A 0.00144 0.00250 2B 0.00188 0.003253A 0.00107 0.00185 3B 0.00139 0.00240

19⁄16 – 20 or 1.5625 – 20 UN 2A 0.00139 0.00240 2B 0.00179 0.003103A 0.00104 0.00180 3B 0.00133 0.00230

15⁄8 – 6 or 1.625 – 6 UN 2A 0.00237 0.00410 2B 0.00309 0.005353A 0.00179 0.00310 3B 0.00231 0.00400

15⁄8 – 8 or 1.625 – 8 UN 2A 0.00214 0.00370 2B 0.00280 0.004853A 0.00162 0.00280 3B 0.00208 0.00360

15⁄8 – 12 or 1.625 – 12 UN 2A 0.00170 0.00295 2B 0.00219 0.003803A 0.00127 0.00220 3B 0.00165 0.00285

15⁄8 – 16 or 1.625 – 16 UN 2A 0.00150 0.00260 2B 0.00196 0.003403A 0.00113 0.00195 3B 0.00147 0.00255

15⁄8 – 18 or 1.625 – 18 UNEF 2A 0.00144 0.00250 2B 0.00188 0.003253A 0.00107 0.00185 3B 0.00130 0.00240

15⁄8 – 20 or 1.625 – 20 UN 2A 0.00139 0.00240 2B 0.00179 0.003103A 0.00104 0.00180 3B 0.00133 0.00230

111⁄16 – 6 or 1.6875 – 6 UN 2A 0.00240 0.00415 2B 0.00312 0.005403A 0.00179 0.00310 3B 0.00234 0.00405

111⁄16 – 8 or 1.6875 – 8 UN 2A 0.00217 0.00375 2B 0.00280 0.004853A 0.00162 0.00280 3B 0.00211 0.00365

45





External Internal



1 2 3 4 5 6 7 8

111⁄16 – 12 or 1.6875 – 12 UN 2A 0.00173 0.00300 2B 0.00225 0.003903A 0.00130 0.00225 3B 0.00167 0.00290

111⁄16 – 16 or 1.6875 – 16 UN 2A 0.00153 0.00265 2B 0.00199 0.003453A 0.00115 0.00200 3B 0.00150 0.00260

111⁄16 – 18 or 1.6875 – 18 UNEF 2A 0.00147 0.00255 2B 0.00191 0.003303A 0.00110 0.00190 3B 0.00141 0.00245

111⁄16 – 20 or 1.6875 – 20 UN 2A 0.00139 0.00240 2B 0.00182 0.003153A 0.00104 0.00180 3B 0.00136 0.00235

13⁄4 – 5 or 1.750 – 5 UNC 1A 0.00387 0.00670 1B 0.00502 0.008702A 0.00257 0.00445 2B 0.00335 0.005803A 0.00193 0.00335 3B 0.00251 0.00435

13⁄4 – 6 or 1.750 – 6 UN 2A 0.00240 0.00415 2B 0.00312 0.005403A 0.00182 0.00315 3B 0.00234 0.00405

13⁄4 – 8 or 1.750 – 8 UN 2A 0.00217 0.00375 2B 0.00283 0.004903A 0.00165 0.00285 3B 0.00214 0.00370

13⁄4 – 12 or 1.750 – 12 UN 2A 0.00173 0.00300 2B 0.00225 0.003903A 0.00130 0.00225 3B 0.00167 0.00290

13⁄4 – 16 or 1.750 – 16 UN 2A 0.00153 0.00265 2B 0.00199 0.003453A 0.00115 0.00200 3B 0.00150 0.00260

13⁄4 – 20 or 1.750 – 20 UN 2A 0.00139 0.00240 2B 0.00182 0.003153A 0.00104 0.00180 3B 0.00136 0.00235

113⁄16 – 6 or 1.8125 – 6 UN 2A 0.00242 0.00420 2B 0.00315 0.005453A 0.00182 0.00315 3B 0.00237 0.00410

113⁄16 – 8 or 1.8125 – 8 UN 2A 0.00219 0.00380 2B 0.00286 0.004953A 0.00165 0.00285 3B 0.00214 0.00370

113⁄16 – 12 or 1.8125 – 12 UN 2A 0.00173 0.00300 2B 0.00225 0.003903A 0.00130 0.00225 3B 0.00167 0.00290

113⁄16 – 16 or 1.8125 – 16 UN 2A 0.00153 0.00265 2B 0.00199 0.003453A 0.00115 0.00200 3B 0.00150 0.00260

113⁄16 – 20 or 1.8125 – 20 UN 2A 0.00139 0.00240 2B 0.00182 0.003153A 0.00104 0.00180 3B 0.00136 0.00235

17⁄8 – 6 or 1.875 – 6 UN 2A 0.00242 0.00420 2B 0.00318 0.005503A 0.00182 0.00315 3B 0.00237 0.00410

17⁄8 – 8 or 1.875 – 8 UN 2A 0.00222 0.00385 2B 0.00289 0.005003A 0.00165 0.00285 3B 0.00217 0.00375

17⁄8 – 12 or 1.875 – 12 UN 2A 0.00173 0.00300 2B 0.00225 0.003903A 0.00130 0.00225 3B 0.00167 0.00290

17⁄8 – 16 or 1.875 – 16 UN 2A 0.00153 0.00265 2B 0.00199 0.003453A 0.00115 0.00200 3B 0.00150 0.00260

17⁄8 – 20 or 1.875 – 20 UN 2A 0.00139 0.00240 2B 0.00182 0.003153A 0.00104 0.00180 3B 0.00136 0.00235

115⁄16 – 6 or 1.9375 – 6 UN 2A 0.00245 0.00425 2B 0.00320 0.005553A 0.00185 0.00320 3B 0.00240 0.00415

46



External Internal



1 2 3 4 5 6 7 8

115⁄16 – 8 or 1.9375 – 8 UN 2A 0.00222 0.00385 2B 0.00289 0.005003A 0.00167 0.00290 3B 0.00217 0.00375

115⁄16 – 12 or 1.9375 – 12 UN 2A 0.00176 0.00305 2B 0.00228 0.003953A 0.00130 0.00225 3B 0.00170 0.00295

115⁄16 – 16 or 1.9375 – 16 UN 2A 0.00156 0.00270 2B 0.00202 0.003503A 0.00115 0.00200 3B 0.00150 0.00260

115⁄16 – 20 or 1.9375 – 20 UN 2A 0.00141 0.00245 2B 0.00185 0.003203A 0.00107 0.00185 3B 0.00139 0.00240

2 – 41⁄2 or 2.000 – 4.5 UNC 1A 0.00413 0.00715 1B 0.00537 0.009302A 0.00274 0.00475 2B 0.00358 0.006203A 0.00205 0.00355 3B 0.00268 0.00465

2 – 6 or 2.000 – 6 UN 2A 0.00248 0.00430 2B 0.00320 0.005553A 0.00185 0.00320 3B 0.00240 0.00415

2 – 8 or 2.000 – 8 UN 2A 0.00225 0.00390 2B 0.00292 0.005053A 0.00167 0.00290 3B 0.00219 0.00380

2 – 12 or 2.000 – 12 UN 2A 0.00176 0.00305 2B 0.00223 0.003953A 0.00130 0.00225 3B 0.00170 0.00295

2 – 16 or 2.000 – 16 UN 2A 0.00156 0.00270 2B 0.00202 0.003503A 0.00115 0.00200 3B 0.00150 0.00260

2 – 20 or 2.000 – 20 UN 2A 0.00141 0.00245 2B 0.00185 0.003203A 0.00107 0.00185 3B 0.00139 0.00240

21⁄8 – 6 or 2.125 – 6 UN 2A 0.00251 0.00435 2B 0.00326 0.005653A 0.00188 0.00325 3B 0.00242 0.00420

21⁄8 – 8 or 2.125 – 8 UN 2A 0.00228 0.00395 2B 0.00294 0.005103A 0.00170 0.00295 3B 0.00212 0.00385

21⁄8 – 12 or 2.125 – 12 UN 2A 0.00176 0.00305 2B 0.00228 0.003953A 0.00130 0.00225 3B 0.00170 0.00295

21⁄8 – 16 or 2.125 – 16 UN 2A 0.00156 0.00270 2B 0.00202 0.003503A 0.00115 0.00200 3B 0.00150 0.00260

21⁄8 – 20 or 2.125 – 20 UN 2A 0.00141 0.00245 2B 0.00185 0.003203A 0.00107 0.00185 3B 0.00139 0.00240

21⁄4 – 41⁄2 or 2.250 – 4.5 UNC 1A 0.00421 0.00730 1B 0.00548 0.009502A 0.00280 0.00485 2B 0.00364 0.006303A 0.00211 0.00365 3B 0.00274 0.00475

21⁄4 – 6 or 2.250 – 6 UN 2A 0.00254 0.00440 2B 0.00329 0.005703A 0.00191 0.00330 3B 0.00214 0.00425

21⁄4 – 8 or 2.250 – 8 UN 2A 0.00231 0.00400 2B 0.00300 0.005203A 0.00173 0.00300 3B 0.00225 0.00390

21⁄4 – 12 or 2.250 – 12 UN 2A 0.00176 0.00305 2B 0.00228 0.003953A 0.00130 0.00225 3B 0.00170 0.00295

21⁄4 – 16 or 2.250 – 16 UN 2A 0.00156 0.00270 2B 0.00202 0.003503A 0.00115 0.00200 3B 0.00150 0.00260

21⁄4 – 20 or 2.250 – 20 UN 2A 0.00141 0.00245 2B 0.00185 0.003203A 0.00107 0.00185 3B 0.00139 0.00240

47





External Internal



1 2 3 4 5 6 7 8

23⁄8 – 6 or 2.375 – 6 UN 2A 0.00257 0.00445 2B 0.00332 0.005753A 0.00191 0.00330 3B 0.00248 0.00430

23⁄8 – 8 or 2.375 – 8 UN 2A 0.00234 0.00405 2B 0.00303 0.005253A 0.00173 0.00300 3B 0.00228 0.00395

23⁄8 – 12 or 2.375 – 12 UN 2A 0.00179 0.00310 2B 0.00234 0.004053A 0.00133 0.00230 3B 0.00173 0.00300

23⁄8 – 16 or 2.375 – 16 UN 2A 0.00159 0.00275 2B 0.00208 0.003603A 0.00118 0.00205 3B 0.00155 0.00270

23⁄8 – 20 or 2.375 – 20 UN 2A 0.00147 0.00255 2B 0.00191 0.003303A 0.00110 0.00190 3B 0.00144 0.00250

21⁄2 – 4 or 2.500 – 4 UNC 1A 0.00447 0.00775 1B 0.00583 0.010102A 0.00300 0.00520 2B 0.00390 0.006753A 0.00225 0.00390 3B 0.00292 0.00505

21⁄2 – 6 or 2.500 – 6 UN 2A 0.00260 0.00450 2B 0.00335 0.005803A 0.00193 0.00335 3B 0.00251 0.00435

21⁄2 – 8 or 2.500 – 8 UN 2A 0.00237 0.00410 2B 0.00306 0.005303A 0.00176 0.00305 3B 0.00231 0.00400

21⁄2 – 12 or 2.500 – 12 UN 2A 0.00179 0.00310 2B 0.00234 0.004053A 0.00133 0.00230 3B 0.00173 0.00300

21⁄2 – 16 or 2.500 – 16 UN 2A 0.00159 0.00275 2B 0.00208 0.003603A 0.00118 0.00205 3B 0.00156 0.00270

21⁄2 – 20 or 2.500 – 20 UN 2A 0.00147 0.00255 2B 0.00191 0.003303A 0.00110 0.00190 3B 0.00144 0.00250

25⁄8 – 6 or 2.625 – 6 UN 2A 0.00260 0.00450 2B 0.00341 0.005903A 0.00196 0.00340 3B 0.00254 0.00440

25⁄8 – 8 or 2.625 – 8 UN 2A 0.00237 0.00410 2B 0.00309 0.005353A 0.00179 0.00310 3B 0.00231 0.00400

25⁄8 – 12 or 2.625 – 12 UN 2A 0.00179 0.00310 2B 0.00234 0.004053A 0.00133 0.00230 3B 0.00173 0.00300

25⁄8 – 16 or 2.625 – 16 UN 2A 0.00159 0.00275 2B 0.00208 0.003603A 0.00118 0.00205 3B 0.00156 0.00270

25⁄8 – 20 or 2.625 – 20 UN 2A 0.00147 0.00255 2B 0.00191 0.003303A 0.00110 0.00190 3B 0.00144 0.00250

23⁄4 – 4 or 2.750 – 4 UNC 1A 0.00456 0.00790 1B 0.00595 0.010302A 0.00303 0.00525 2B 0.00395 0.006853A 0.00228 0.00395 3B 0.00297 0.00515

23⁄4 – 6 or 2.750 – 6 UN 2A 0.00263 0.00455 2B 0.00344 0.005953A 0.00196 0.00340 3B 0.00257 0.00445

23⁄4 – 8 or 2.750 – 8 UN 2A 0.00240 0.00415 2B 0.00312 0.005403A 0.00182 0.00315 3B 0.00234 0.00405

23⁄4 – 12 or 2.750 – 12 UN 2A 0.00179 0.00310 2B 0.00234 0.004053A 0.00133 0.00230 3B 0.00173 0.00300

48



External Internal


and Series in Lead, Diameter, in., in Lead, Diameter, in.Threads/in. Designation Class in. (±) 1⁄2Td2(+) Class in. (±) 1⁄2TD2 (−)

1 2 3 4 5 6 7 8

23⁄4 – 16 or 2.750 – 16 UN 2A 0.00159 0.00275 2B 0.00208 0.003603A 0.00118 0.00205 3B 0.00156 0.00270

23⁄4 – 20 or 2.750 – 20 UN 2A 0.00147 0.00255 2B 0.00191 0.003303A 0.00110 0.00190 3B 0.00144 0.00250

27⁄8 – 6 or 2.875 – 6 UN 2A 0.00266 0.00460 2B 0.00346 0.006003A 0.00199 0.00345 3B 0.00280 0.00450

27⁄8 – 8 or 2.875 – 8 UN 2A 0.00242 0.00420 2B 0.00318 0.005503A 0.00182 0.00315 3B 0.00237 0.00410

27⁄8 – 12 or 2.875 – 12 UN 2A 0.00182 0.00315 2B 0.00237 0.004103A 0.00136 0.00235 3B 0.00179 0.00310

27⁄8 – 16 or 2.875 – 16 UN 2A 0.00162 0.00280 2B 0.00211 0.003653A 0.00121 0.00210 3B 0.00159 0.00275

27⁄8 – 20 or 2.875 – 20 UN 2A 0.00150 0.00260 2B 0.00196 0.003403A 0.00113 0.00195 3B 0.00147 0.00255

3 – 4 or 3.000 – 4 UNC 1A 0.00465 0.00805 1B 0.00603 0.010452A 0.00309 0.00535 2B 0.00401 0.006953A 0.00231 0.00400 3B 0.00300 0.00520

3 – 6 or 3.000 – 6 UN 2A 0.00268 0.00465 2B 0.00349 0.006053A 0.00202 0.00350 3B 0.00263 0.00455

3 – 8 or 3.000 – 8 UN 2A 0.00245 0.00425 2B 0.00320 0.005553A 0.00185 0.00320 3B 0.00240 0.00415

3 – 12 or 3.000 – 12 UN 2A 0.00182 0.00315 2B 0.00237 0.004103A 0.00136 0.00235 3B 0.00179 0.00310

3 – 16 or 3.000 – 16 UN 2A 0.00162 0.00280 2B 0.00211 0.003653A 0.00121 0.00210 3B 0.00159 0.00275

3 – 20 or 3.000 – 20 UN 2A 0.00150 0.00260 2B 0.00196 0.003403A 0.00113 0.00195 3B 0.00147 0.00255

31⁄8 – 6 or 3.125 – 6 UN 2A 0.00271 0.00470 2B 0.00352 0.006103A 0.00202 0.00350 3B 0.00266 0.00460

31⁄8 – 8 or 3.125 – 8 UN 2A 0.00248 0.00430 2B 0.00323 0.005603A 0.00185 0.00320 3B 0.00242 0.00420

31⁄8 – 12 or 3.125 – 12 UN 2A 0.00182 0.00315 2B 0.00237 0.004103A 0.00136 0.00235 3B 0.00179 0.00310

31⁄8 – 16 or 3.125 – 16 UN 2A 0.00162 0.00280 2B 0.00211 0.003653A 0.00121 0.00210 3B 0.00159 0.00275

31⁄4 – 4 or 3.250 – 4 UNC 1A 0.00471 0.00815 1B 0.00612 0.010602A 0.00315 0.00545 2B 0.00407 0.007053A 0.00237 0.00410 3B 0.00306 0.00530

31⁄4 – 6 or 3.250 – 6 UN 2A 0.00274 0.00475 2B 0.00355 0.006153A 0.00205 0.00355 3B 0.00266 0.00460

31⁄4 – 8 or 3.250 – 8 UN 2A 0.00251 0.00435 2B 0.00326 0.005653A 0.00188 0.00325 3B 0.00245 0.00425

31⁄4 – 12 or 3.250 – 12 UN 2A 0.00182 0.00315 2B 0.00237 0.004103A 0.00136 0.00235 3B 0.00179 0.00310

49





External Internal



1 2 3 4 5 6 7 8

31⁄4 – 16 or 3.250 – 16 UN 2A 0.00162 0.00280 2B 0.00211 0.003653A 0.00121 0.00210 3B 0.00159 0.00275

33⁄8 – 6 or 3.375 – 6 UN 2A 0.00274 0.00475 2B 0.00358 0.006203A 0.00208 0.00360 3B 0.00258 0.00465

33⁄8 – 8 or 3.375 – 8 UN 2A 0.00254 0.00440 2B 0.00329 0.005703A 0.00191 0.00330 3B 0.00245 0.00425

33⁄8 – 12 or 3.375 – 12 UN 2A 0.00185 0.00320 2B 0.00242 0.004203A 0.00139 0.00242 3B 0.00182 0.00315

33⁄8 – 16 or 3.375 – 16 UN 2A 0.00167 0.00290 2B 0.00217 0.003753A 0.00124 0.00215 3B 0.00162 0.00280

31⁄2 – 4 or 3.500 – 4 UNC 1A 0.00479 0.00830 1B 0.00621 0.010752A 0.00318 0.00550 2B 0.00413 0.007153A 0.00240 0.00415 3B 0.00312 0.00540

31⁄2 – 6 or 3.500 – 6 UN 2A 0.00277 0.00480 2B 0.00361 0.006253A 0.00208 0.00360 3B 0.00271 0.00470

31⁄2 – 8 or 3.500 – 8 UN 2A 0.00254 0.00440 2B 0.00332 0.005753A 0.00191 0.00330 3B 0.00248 0.00430

31⁄2 – 12 or 3.500 – 12 UN 2A 0.00185 0.00320 2B 0.00242 0.004203A 0.00139 0.00240 3B 0.00182 0.00315

31⁄2 – 16 or 3.500 – 16 UN 2A 0.00167 0.00290 2B 0.00217 0.003753A 0.00124 0.00215 3B 0.00162 0.00280

35⁄8 – 6 or 3.625 – 6 UN 2A 0.00280 0.00485 2B 0.00364 0.006303A 0.00211 0.00365 3B 0.00274 0.00475

35⁄8 – 8 or 3.625 – 8 UN 2A 0.00257 0.00445 2B 0.00335 0.005803A 0.00193 0.00335 3B 0.00251 0.00435

35⁄8 – 12 or 3.625 – 12 UN 2A 0.00185 0.00320 2B 0.00242 0.004203A 0.00139 0.00240 3B 0.00182 0.00315

35⁄8 – 16 or 3.625 – 16 UN 2A 0.00167 0.00290 2B 0.00217 0.003753A 0.00214 0.00215 3B 0.00162 0.00280

33⁄4 – 4 or 3.750 – 4 UNC 1A 0.00485 0.00840 1B 0.00629 0.010902A 0.00323 0.00560 2B 0.00419 0.007253A 0.00242 0.00420 3B 0.00315 0.00545

33⁄4 – 6 or 3.750 – 6 UN 2A 0.00283 0.00490 2B 0.00367 0.006353A 0.00211 0.00365 3B 0.00274 0.00475

33⁄4 – 8 or 3.750 – 8 UN 2A 0.00260 0.00450 2B 0.00338 0.005853A 0.00193 0.00335 3B 0.00254 0.00440

33⁄4 – 12 or 3.750 – 12 UN 2A 0.00185 0.00320 2B 0.00242 0.004203A 0.00139 0.00240 3B 0.00182 0.00315

33⁄4 – 16 or 3.750 – 16 UN 2A 0.00167 0.00290 2B 0.00217 0.003753A 0.00124 0.00215 3B 0.00162 0.00280

37⁄8 – 6 or 3.875 – 6 UN 2A 0.00286 0.00495 2B 0.00369 0.006403A 0.00214 0.00370 3B 0.00277 0.00480

50



External Internal



1 2 3 4 5 6 7 8

37⁄8 – 8 or 3.875 – 8 UN 2A 0.00263 0.00455 2B 0.00341 0.005903A 0.00196 0.00340 3B 0.00254 0.00440

37⁄8 – 12 or 3.875 – 12 UN 2A 0.00188 0.00325 2B 0.00245 0.004253A 0.00141 0.00245 3B 0.00185 0.00320

37⁄8 – 16 or 3.875 – 16 UN 2A 0.00170 0.00295 2B 0.00219 0.003803A 0.00127 0.00220 3B 0.00165 0.00285

4 – 4 or 4.000 – 4 UNC 1A 0.00491 0.00850 1B 0.00638 0.011052A 0.00326 0.00565 2B 0.00424 0.007353A 0.00245 0.00425 3B 0.00320 0.00555

4 – 6 or 4.000 – 6 UN 2A 0.00286 0.00495 2B 0.00372 0.006453A 0.00214 0.00370 3B 0.00280 0.00485

4 – 8 or 4.000 – 8 UN 2A 0.00263 0.00455 2B 0.00344 0.005953A 0.00196 0.00340 3B 0.00257 0.00445

4 – 12 or 4.000 – 12 UN 2A 0.00188 0.00325 2B 0.00245 0.004253A 0.00141 0.00245 3B 0.00185 0.00320

4 – 16 or 4.000 – 16 UN 2A 0.00170 0.00295 2B 0.00219 0.003803A 0.00127 0.00220 3B 0.00165 0.00285

41⁄8 – 6 or 4.125 – 6 UN 2A 0.00289 0.00500 2B 0.00375 0.006503A 0.00217 0.00375 3B 0.00280 0.00485

41⁄8 – 8 or 4.125 – 8 UN 2A 0.00266 0.00460 2B 0.00346 0.006003A 0.00199 0.00345 3B 0.00260 0.00450

41⁄8 – 12 or 4.125 – 12 UN 2A 0.00188 0.00325 2B 0.00245 0.004253A 0.00141 0.00245 3B 0.00185 0.00320

41⁄8 – 16 or 4.125 – 16 UN 2A 0.00170 0.00295 2B 0.00219 0.003803A 0.00127 0.00220 3B 0.00165 0.00285

41⁄4 – 4 or 4.250 – 4 UN 2A 0.00332 0.00575 2B 0.00430 0.007453A 0.00248 0.00430 3B 0.00323 0.00560

41⁄4 – 6 or 4.250 – 6 UN 2A 0.00292 0.00505 2B 0.00378 0.006553A 0.00217 0.00375 3B 0.00283 0.00490

41⁄4 – 8 or 4.250 – 8 UN 2A 0.00268 0.00465 2B 0.00346 0.006003A 0.00202 0.00350 3B 0.00263 0.00455

41⁄4 – 12 or 4.250 – 12 UN 2A 0.00188 0.00325 2B 0.00245 0.004253A 0.00141 0.00245 3B 0.00185 0.00320

41⁄4 – 16 or 4.250 – 16 UN 2A 0.00170 0.00295 2B 0.00219 0.003803A 0.00127 0.00220 3B 0.00165 0.00285

43⁄8 – 6 or 4.375 – 6 UN 2A 0.00292 0.00505 2B 0.00381 0.006603A 0.00219 0.00380 3B 0.00286 0.00495

43⁄8 – 8 or 4.375 – 8 UN 2A 0.00268 0.00465 2B 0.00346 0.006003A 0.00202 0.00350 3B 0.00263 0.00455

43⁄8 – 12 or 4.375 – 12 UN 2A 0.00188 0.00325 2B 0.00245 0.004253A 0.00141 0.00245 3B 0.00185 0.00320

43⁄8 – 16 or 4.375 – 16 UN 2A 0.00170 0.00295 2B 0.00219 0.003803A 0.00127 0.00220 3B 0.00165 0.00285

51





External Internal



1 2 3 4 5 6 7 8

41⁄2 – 4 or 4.500 – 4 UN 2A 0.00335 0.00580 2B 0.00436 0.007553A 0.00251 0.00435 3B 0.00326 0.00565

41⁄2 – 6 or 4.500 – 6 UN 2A 0.00294 0.00510 2B 0.00384 0.006653A 0.00222 0.00385 3B 0.00286 0.00495

41⁄2 – 8 or 4.500 – 8 UN 2A 0.00271 0.00470 2B 0.00352 0.006103A 0.00205 0.00355 3B 0.00266 0.00460

41⁄2 – 12 or 4.500 – 12 UN 2A 0.00188 0.00325 2B 0.00245 0.004253A 0.00141 0.00245 3B 0.00185 0.00320

41⁄2 – 16 or 4.500 – 16 UN 2A 0.00170 0.00295 2B 0.00219 0.003803A 0.00127 0.00220 3B 0.00165 0.00285

45⁄8 – 6 or 4.625 – 6 UN 2A 0.00297 0.00515 2B 0.00384 0.006653A 0.00222 0.00385 3B 0.00289 0.00500

45⁄8 – 8 or 4.625 – 8 UN 2A 0.00274 0.00475 2B 0.00358 0.006203A 0.00205 0.00355 3B 0.00268 0.00465

45⁄8 – 12 or 4.625 – 12 UN 2A 0.00193 0.00335 2B 0.00251 0.004353A 0.00144 0.00250 3B 0.00191 0.00330

45⁄8 – 16 or 4.625 – 16 UN 2A 0.00176 0.00305 2B 0.00228 0.003953A 0.00130 0.00225 3B 0.00170 0.00295

43⁄4 – 4 or 4.750 – 4 UN 2A 0.00338 0.00585 2B 0.00442 0.007653A 0.00254 0.00440 3B 0.00329 0.00570

43⁄4 – 6 or 4.750 – 6 UN 2A 0.00297 0.00515 2B 0.00387 0.006703A 0.00222 0.00385 3B 0.00292 0.00505

43⁄4 – 8 or 4.750 – 8 UN 2A 0.00274 0.00475 2B 0.00358 0.006203A 0.00205 0.00355 3B 0.00268 0.00465

43⁄4 – 12 or 4.750 – 12 UN 2A 0.00193 0.00335 2B 0.00251 0.004353A 0.00144 0.00250 3B 0.00191 0.00330

43⁄4 – 16 or 4.750 – 16 UN 2A 0.00176 0.00305 2B 0.00228 0.003953A 0.00130 0.00225 3B 0.00170 0.00295

47⁄8 – 6 or 4.875 – 6 UN 2A 0.00300 0.00520 2B 0.00390 0.006753A 0.00225 0.00390 3B 0.00292 0.00505

47⁄8 – 8 or 4.875 – 8 UN 2A 0.00277 0.00480 2B 0.00361 0.006253A 0.00208 0.00360 3B 0.00271 0.00470

47⁄8 – 12 or 4.875 – 12 UN 2A 0.00193 0.00335 2B 0.00251 0.004353A 0.00144 0.00250 3B 0.00101 0.00330

47⁄8 – 16 or 4.875 – 16 UN 2A 0.00176 0.00305 2B 0.00228 0.003953A 0.00130 0.00225 3B 0.00170 0.00295

5 – 4 or 5.000 – 4 UN 2A 0.00344 0.00595 2B 0.00445 0.007703A 0.00257 0.00445 3B 0.00335 0.00580

5 – 6 or 5.000 – 6 UN 2A 0.00303 0.00525 2B 0.00393 0.006803A 0.00225 0.00390 3B 0.00294 0.00510

52



External Internal



1 2 3 4 5 6 7 8

5 – 8 or 5.000 – 8 UN 2A 0.00280 0.00485 2B 0.00364 0.006303A 0.00211 0.00365 3B 0.00274 0.00475

5 – 12 or 5.000 – 12 UN 2A 0.00193 0.00335 2B 0.00251 0.004353A 0.00144 0.00250 3B 0.00191 0.00330

5 – 16 or 5.000 – 16 UN 2A 0.00176 0.00305 2B 0.00228 0.003053A 0.00130 0.00225 3B 0.00170 0.00295

51⁄8 – 8 or 5.125 – 8 UN 2A 0.00280 0.00485 2B 0.00364 0.006303A 0.00211 0.00365 3B 0.00274 0.00475

51⁄8 – 12 or 5.125 – 12 UN 2A 0.00193 0.00335 2B 0.00251 0.004353A 0.00144 0.00250 3B 0.00191 0.00330

51⁄8 – 16 or 5.125 – 16 UN 2A 0.00176 0.00305 2B 0.00228 0.003953A 0.00130 0.00225 3B 0.00170 0.00295

51⁄4 – 4 or 5.250 – 4 UN 2A 0.00346 0.00600 2B 0.00450 0.007803A 0.00260 0.00450 3B 0.00385 0.00585

51⁄4 – 8 or 5.250 – 8 UN 2A 0.00283 0.00490 2B 0.00367 0.006353A 0.00214 0.00370 3B 0.00277 0.00480

51⁄4 – 12 or 5.250 – 12 UN 2A 0.00193 0.00335 2B 0.00251 0.004353A 0.00144 0.00250 3B 0.00191 0.00330

51⁄4 – 16 or 5.250 – 16 UN 2A 0.00176 0.00305 2B 0.00228 0.003953A 0.00130 0.00225 3B 0.00170 0.00295

53⁄8 – 8 or 5.375 – 8 UN 2A 0.00286 0.00495 2B 0.00372 0.006453A 0.00214 0.00370 3B 0.00280 0.00485

53⁄8 – 12 or 5.375 – 12 UN 2A 0.00193 0.00335 2B 0.00251 0.004353A 0.00144 0.00250 3B 0.00191 0.00330

53⁄8 – 16 or 5.375 – 16 UN 2A 0.00176 0.00305 2B 0.00231 0.003953A 0.00130 0.00225 3B 0.00170 0.00295

51⁄2 – 4 or 5.500 – 4 UN 2A 0.00349 0.00605 2B 0.00456 0.007903A 0.00263 0.00455 3B 0.00341 0.00500

51⁄2 – 8 or 5.500 – 8 UN 2A 0.00286 0.00495 2B 0.00372 0.006453A 0.00214 0.00370 3B 0.00280 0.00485

51⁄2 – 12 or 5.500 – 12 UN 2A 0.00193 0.00335 2B 0.00251 0.004353A 0.00144 0.00250 3B 0.00191 0.00330

51⁄2 – 16 or 5.500 – 16 UN 2A 0.00176 0.00305 2B 0.00228 0.003953A 0.00130 0.00225 3B 0.00170 0.00295

55⁄8 – 8 or 5.625 – 8 UN 2A 0.00289 0.00500 2B 0.00375 0.006503A 0.00217 0.00375 3B 0.00283 0.00490

55⁄8 – 12 or 5.625 – 12 UN 2A 0.00199 0.00345 2B 0.00260 0.004503A 0.00150 0.00260 3B 0.00193 0.00335

55⁄8 – 16 or 5.625 – 16 UN 2A 0.00179 0.00310 2B 0.00234 0.004053A 0.00136 0.00235 3B 0.00176 0.00305

53⁄4 – 4 or 5.750 – 4 UN 2A 0.00352 0.00610 2B 0.00459 0.007953A 0.00266 0.00460 3B 0.00344 0.00595

53





External Internal

Allowable Allowable Equivalent ChangeNominal Size Variation Equivalent Change Variation in Functional

and Series in Lead, in. in Functional in Lead, in. Diameter, in.Threads/in. Designation Class (±) Diameter, 1⁄2Td2 Class (±) 1⁄2TD2 (−)

1 2 3 4 5 6 7 8

53⁄4 – 8 or 5.750 – 8 UN 2A 0.00289 0.00500 2B 0.00375 0.006503A 0.00217 0.00375 3B 0.00283 0.00490

53⁄4 – 12 or 5.750 – 12 UN 2A 0.00199 0.00345 2B 0.00260 0.004503A 0.00150 0.00260 3B 0.00193 0.00335

53⁄4 – 16 or 5.750 – 16 UN 2A 0.00179 0.00310 2B 0.00234 0.004053A 0.00136 0.00235 3B 0.00176 0.00305

57⁄8 – 8 or 5.875 – 8 UN 2A 0.00292 0.00505 2B 0.00378 0.006553A 0.00219 0.00380 3B 0.00283 0.00490

57⁄8 – 12 or 5.875 – 12 UN 2A 0.00199 0.00345 2B 0.00260 0.004503A 0.00150 0.00260 3B 0.00193 0.00335

57⁄8 – 16 or 5.875 – 16 UN 2A 0.00179 0.00310 2B 0.00234 0.004053A 0.00136 0.00235 3B 0.00176 0.00305

6 – 4 or 6.000 – 4 UN 2A 0.00358 0.00620 2B 0.00455 0.008053A 0.00268 0.00465 3B 0.00346 0.00600

6 – 8 or 6.000 – 8 UN 2A 0.00294 0.00510 2B 0.00384 0.006653A 0.00222 0.00385 3B 0.00286 0.00495

6 – 12 or 6.000 – 12 UN 2A 0.00199 0.00315 2B 0.00260 0.004503A 0.00150 0.00260 3B 0.00193 0.00335

6 – 16 or 6.000 – 16 UN 2A 0.00179 0.00310 2B 0.00234 0.004053A 0.00136 0.00235 3B 0.00176 0.00305

5.3.2 Long Length of Engagement Using StandardThread Gage Limits. ASME B1.2 recommends that thelength of the GO gage should approximate the lengthof engagement. However, it is sometimes more economi-cal to accept these threads with GO thread gages madefrom standard gage blanks (refer to ASME B47.1), whichhave length approximating the standard lengths ofengagement.

NOTE: When this is done, additional precautions are necessaryto determine the effect of cumulative variation of lead andstraightness of thread axis due to a long length of engagement.

If applicable, an additional allowance should be provided, pref-erably on the external thread, the amount of which should bethe diameter equivalent of the cumulative lead variation for theincreased length of engagement, equal to the sum of one-half thepitch diameter tolerances of the external and internal threadsallowed for the standard length of engagement.

EXAMPLE: 0.3750-24UNF-2A; LEp0.88 in. (2.35 diameters); withexternal and internal thread gages of standard length.

Add allowance equal to 1⁄2Td2 + 1⁄2TD2 for standard matingthreads. From Table 3, column 5, 1⁄2Td2 (standard)p0.0019.

From Table 3, column 8, 1⁄2TD2 (standard)p0.00245.The sum of these, after rounding, is equal to 0.0044, which is the

added allowance. Therefore, the thread is redesignated to indicate a

54

nonstandard external thread, with the allowance of 0.0044 sub-tracted from the basic size of 0.3750. New designation is 0.3706-24UNS-2A. The added allowance is also subtracted from the stan-dard major diameter and pitch diameter size limits. See para. 6.6.2.

5.4 Minor Diameter Tolerance and Allowance forExternal Threads

The tolerance for minor diameter is for reference only.In dimensioning external threads, the minimum minordiameter is not specified, being established by the crestof an unworn tool. In practice, the minor diameter ofan external thread is satisfactory when accepted by agage or gaging method that represents the maximum-material condition of the internal thread less the allow-ance, es, if any. A formula for the minor diameter toler-ance of external threads is given in para. 5.8.1(d).

5.5 Major Diameter Tolerance for Internal Threads

The tolerance for major diameter is for reference only.In dimensioning internal threads, the maximum majordiameter is not specified, being established by the crestof an unworn tool. In practice, the major diameter ofan internal thread is satisfactory when accepted by a


gage or gaging method that represents the maximum-material condition of an external thread which has noallowance. A formula for the major diameter toleranceof internal threads is given in para. 5.8.2(a).

5.6 Minor Diameter Tolerance and Length ofEngagement for Internal Threads

Formulas for the minor diameter tolerance for internalthreads are given in para. 5.8.2(c).

Internal thread minor diameter tolerances are suitablefor lengths of engagement up to 1.5 diameters. For appli-cations having shorter or longer lengths of engagement,it may be advantageous to decrease or increase the toler-ance as explained in para. 5.6.1.

5.6.1 The principal practical factors that governminor diameter tolerance are ease of tapping, standarddrill sizes, and height of engagement.NOTE: Height of engagement is measured in a radial direction,while length of engagement is measured in an axial direction.

Height of engagement correlates with the strippingstrength of the thread assembly and, therefore, also withthe length of engagement. It also correlates with thetendency toward disengagement of the threads on oneside when assembly is eccentric. The amount of possibleeccentricity is one-half of the sum of the allowance andpitch diameter tolerances on both mating threads. Fora given pitch, or height of thread, this sum increaseswith the diameter, and accordingly, this factor wouldrequire a decrease in minor diameter tolerance with anincrease in thread diameter. However, such a decreasein tolerance often is not feasible without requiring spe-cial drill sizes; therefore, to be able to use as many aspossible of the available standard drill sizes listed inASME B94.11M, the minor diameter tolerance forClasses 1B and 2B of a given pitch for 1⁄4 in. diameterand larger is constant.

There may be applications where the lengths ofengagement of the mating threads or the combinationof materials used for mating threads are such that themaximum tolerance may not provide the desiredstrength of the fastening. Experience has shown that forlengths of engagement less than 0.67D (the minimumthickness of standard nuts), the minor diameter toler-ance may be reduced without causing tapping diffi-culties.

In other applications, the length of engagement ofmating threads may be long because of design considera-tions or the combination of materials used for matingthreads. As the threads engaged increase in number,their height of engagement may be shallower and stilldevelop stripping strength greater than the externalthread breaking strength. In these cases, the maximumtolerance should be increased to reduce the possibilityof tapping difficulties.

It is particularly important to reduce the number ofminor diameter tolerances to a practical minimum. This

55

reduction is usually obvious to the producer of longerinternally threaded components, but sometimes is notunderstood by the user.

The tolerances for lengths of engagement less than0.33D are 0.50 times the formula values in para. 5.8.2(c). For lengths of engagement from 0.33D to 0.67D, thetolerances are 0.75 times the formula values; for lengthsof engagement from 0.67D to 1.5D, the tolerances areequal to the formula values; and for lengths of engage-ment over 1.5D, the tolerances are 1.25 times the formulavalues. Where the tolerance value so computed is morethan 0.394P, the value is adjusted to equal 0.394P.

5.7 Disposition of Allowance and Tolerance

The disposition of allowance, tolerance, and crestclearances for the various thread classes is shown inFigs. 2 and 3.

5.8 Formulas for Allowance and Tolerance

The following formulas for allowance and toleranceare used for unified formulation and apply to standardand special series screw threads.

The following symbols are used in the equations:D bscp basic major (nominal) diameter

LE p length of engagement, in.P p pitch, in.p 1/nH p height of fundamental triangle

p 0.86602540Pn p threads per inch

5.8.1 External Thread(a) Allowance (External Threads)

(1) Classes 1A and 2A p 0.300 Class 2A pitch diam-eter tolerance1

(2) Class 3A p no allowance

(b) Major Diameter Tolerance (External Threads)(1) Class 1A p 0.090 3�P 2

(2) Classes 2A and 3A p 0.060 3�P2

The tolerance for Class 2A coarse and the 8-threadseries threads of unfinished, hot-rolled material is0.0903�P2. This does not apply to standard fasteners withrolled threads.

(c) Pitch Diameter Tolerance (External Threads)(1) Class 1A p 1.500 Class 2A pitch diameter tol-

erance1

(2) Class 2A p 0.0015 3�D + 0.0015 �LE + 0.015 3�P 2

NOTE: See Table 4 for the values of these terms corresponding togiven values of diameter, length of engagement.1

(3) Class 3A p 0.750 Class 2A pitch diameter tol-erance1

1 Calculations shall use Class 2A pitch diameter tolerance withsix decimal places. Final values shall be rounded to four deci-mal places.




Tabl

e4

Incr

emen

tsin

Pitc

hD

iam

eter

Tole

ranc

e—

Clas

s2A

�PD

Tole

ranc

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0.00

153 �

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0.00

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rfo

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Siz

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ILE

0.00

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izes

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0.06

000.

0005

871.

9375

0.00

1870

#0..

...

.0.

0600

0.00

0367

1 ⁄ 218

400.

5000

0.00

1061

23 ⁄ 8..

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3750

0.00

2312

800.

0008

080.

0625

0.00

0595

2.00

000.

0018

901 ⁄ 1

6..

...

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0625

0.00

0375

...

...

360.

5556

0.00

1118

21 ⁄ 28

2.50

000.

0023

7272

0.00

0867

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300.

0006

272.

1250

0.00

1928

#1..

...

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0730

0.00

0405

9 ⁄ 16

16..

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25 ⁄ 8..

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6250

0.00

2430

640.

0009

380.

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0.00

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0019

663 ⁄ 6

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5 ⁄ 8..

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0.62

500.

0011

8623 ⁄ 4

...

2.75

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0024

8760

0.00

0979

0.09

380.

0006

822.

3750

0.00

2001

#2..

...

.0.

0860

0.00

0440

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0.09

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5911

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0007

232.

6250

0.00

2069

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360.

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0.00

0750

2.75

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0021

027 ⁄ 6

4..

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1094

0.00

0496

...

...

280.

7143

0.00

1268

31 ⁄ 8..

.3.

1250

0.00

2652

440.

0012

040.

1380

0.00

0775

2.87

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0021

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...

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9131 ⁄ 4

...

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0.00

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0000

0.00

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99..

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0027

3940

0.00

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593.

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2193

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0.12

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0005

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1 ⁄ 2..

.0.

7826

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1327

33 ⁄ 8..

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3750

0.00

2756

360.

0013

760.

1900

0.00

0862

3.25

000.

0022

22#6

...

..0.

1380

0.00

0557

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8125

0.00

1352

31 ⁄ 2..

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5000

0.00

2806

340.

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290.

2160

0.00

0900

3.37

500.

0022

50..

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...

0.14

060.

0005

62..

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...

0.81

820.

0013

5735 ⁄ 8

...

3.62

500.

0028

5632

0.00

1488

0.25

000.

0009

453.

5000

0.00

2277

5 ⁄ 32

...

...

0.15

620.

0005

93..

...

.24

0.83

330.

0013

6933 ⁄ 4

...

3.75

000.

0029

0530

0.00

1554

0.31

250.

0010

183.

6250

0.00

2304

...

56..

.0.

1607

0.00

0601

7 ⁄ 8..

...

.0.

8750

0.00

1403

37 ⁄ 8..

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8750

0.00

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280.

0016

27

0.37

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0010

823.

7500

0.00

2330

#8..

...

.0.

1640

0.00

0607

...

10..

.0.

9000

0.00

1423

45

4.00

000.

0030

0027

0.00

1667

0.43

750.

0011

393.

8750

0.00

2356

11⁄ 6

4..

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6..

...

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0.00

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0.00

3047

260.

0017

090.

5000

0.00

1191

4.00

000.

0023

813 ⁄ 1

648

...

0.18

750.

0006

501

920

1.00

000.

0015

0041 ⁄ 4

...

4.25

000.

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9224

0.00

1803

0.56

250.

0012

384.

1250

0.00

2406

#10

...

...

0.19

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0006

5411 ⁄ 1

6..

...

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0.00

1546

43 ⁄ 8..

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3750

0.00

3137

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0019

100.

6250

0.00

1282

4.25

000.

0024

3013

⁄ 64

...

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0.20

310.

0006

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110.

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81..

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4.44

440.

0031

6220

0.00

2036

0.68

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244.

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0.00

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...

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0.00

0678

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...

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0015

9141 ⁄ 2

...

4.50

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8218

0.00

2184

0.75

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634.

5000

0.00

2476

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600.

0006

9713 ⁄ 1

6..

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1875

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1635

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0.00

3226

160.

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620.

8125

0.00

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0024

997 ⁄ 3

2..

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2188

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0007

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54

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5412

0.00

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1.00

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005.

0000

0.00

2565

1 ⁄ 436

800.

2500

0.00

0750

13 ⁄ 8..

...

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3750

0.00

1759

51 ⁄ 8..

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1250

0.00

3396

111 ⁄ 2

0.00

2944

1.06

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0015

315.

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0.00

2586

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2656

0.00

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...

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141.

4286

0.00

1793

51 ⁄ 4..

.5.

2500

0.00

3437

110.

0030

331.

1250

0.00

1560

5.25

000.

0026

07..

...

.72

0.27

780.

0007

9117 ⁄ 1

6..

...

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4375

0.00

1798

53 ⁄ 8..

.5.

3750

0.00

3478

100.

0032

321.

1875

0.00

1588

5.37

500.

0026

28..

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...

0.28

120.

0007

9511 ⁄ 2

6..

.1.

5000

0.00

1837

51 ⁄ 2..

.5.

5000

0.00

3518

90.

0034

671.

2500

0.00

1616

5.50

000.

0026

4819

⁄ 64

...

...

0.29

690.

0008

17..

...

.13

1.53

850.

0018

6155 ⁄ 8

...

5.62

500.

0035

588

0.00

3750

56


Tabl

e4

Incr

emen

tsin

Pitc

hD

iam

eter

Tole

ranc

e—

Clas

s2A

(Con

t’d)

�PD

Tole

ranc

ep

0.00

153 �

D+

0.00

15�

LE+

0.01

53 �P

2 �

Leng

thof

Enga

gem

ent,

LE

Bas

edon

Bas

edon

Not

e(1

)B

ased

onN

ote

(1)

Not

e(1

)

Dia

met

er,

DPi

tch,

P1

D9P

20P

1D

9P20

P1

D20

Pfo

rfo

rfo

rfo

rfo

rfo

rfo

rfo

rTh

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57




(d) Minor Diameter Tolerance (External Threads)(1) UNR Classes. To intersection of rounded root

with its centerline (see Figs. 2 and 3), equals pitch diame-ter tolerance for class of thread specified, plus0.10825318P (see Table 5).

(2) UN Classes 1A, 2A, and 3A. To intersection offlat root with flanks of threads (see Figs. 2 and 3), equalspitch diameter tolerance for class of thread specified,plus 0.21650635P (see Table 5).

5.8.2 Internal Thread(a) Major Diameter Tolerance (Internal Threads)

(1) For Classes 1B, 2B, and 3B, equals 0.14433757P(see Table 5) plus the pitch diameter tolerance of theclass of thread under consideration.

(b) Pitch Diameter Tolerance (Internal Threads)(1) Class 1B p 1.950 Class 2A pitch diameter toler-

ance (nominally equal to 1.5 Class 2B)1 (see page 55 forfootnote)

(2) Class 2B p 1.300 Class 2A pitch diameter tol-erance1

(3) Class 3B p 0.975 Class 2A pitch diameter toler-ance (nominally equal to 0.750 Class 2B)1

(c) Minor Diameter Tolerance (Internal Threads)(1) Classes 1B and 2B. For all thread series

and special threads in sizes less than 1 ⁄4 in., equals[0.0500 3�P 2 + 0.03 P/D] − 0.002 in., within the followinglimitations:

(a) Tolerances shall not be greater than 0.39400P.(b) Tolerances shall not be less than 0.2500P −

0.400P2

The formulas are suitable for general applications hav-ing lengths of engagement up to 1.5 diameters.

For all thread series and special threads 1⁄4 in. andlarger, 80 to 4 threads per inch, inclusive, equals 0.25P− 0.4P2. For all thread series and special threads 1⁄4 in.and larger with less than 4 threads per inch, equals 0.15P.

(2) Class 3B. For all thread series, equals[0.05 3�P 2 + 0.03 P/D] − 0.002 in., within the followinglimitations:

(a) Tolerance shall be not greater than 0.394P.(b) Tolerance shall be not less than

(1) for 80 to 13 threads per inch, inclusive,0.23P − 1.5P2

(2) for 12 threads per inch and coarser, 0.120PThe formulas are suitable for general applications hav-

ing lengths of engagement up to 1.5 diameters.

5.9 Lead and Flank Angle Tolerances

See para. 9.

5.10 Coated or Plated Threads

See para. 7 for dimensional accommodation and limitsfor coated threads.

58

5.11 Circular Runout

5.11.1 Circular Runout Is the Full Indicator Movement(FIM) (See ASME Y14.5). Runout of the crest (minor diam-eter of internal thread or major diameter of externalthread) relative to the functional diameter cylinder shallnot be so great that the basic profile is transgressed.

5.11.2 Internal Thread. Maximum runout, which willmaintain the crest inside the basic thread profile, is thedifference between the measured minor diameter andthe basic minor diameter. An out-of-round functionaldiameter cylinder may reduce the available runout.

5.11.3 External Thread. Maximum runout, which willmaintain the crest inside the basic thread profile, is thedifference between the measured major diameter andthe basic major diameter. An out-of-round functionaldiameter cylinder may reduce the available runout.

6 SCREW THREAD DESIGNATION

6.1 Basic Method of Designating

The designation specifies in sequence the nominalsize, number of threads per inch, thread series symbol,thread class symbol, and gaging system per ASME B1.3(see screw thread designations listed at the end of thisparagraph). The nominal size is the basic major diameterand is specified as the fractional diameter, screw number,or their decimal equivalent. Where decimal equivalentsare used for size callout, they shall be shown in fourplace decimals (omitting the cipher in the fourth place)for fractional sizes, and in three place decimals for num-ber sizes. They shall be interpreted as being nominalsize designations only and shall have no dimensionalsignificance beyond the fractional size or number desig-nation. The thread series symbol indicates the threadform (see para. 2), series, and tolerance formulation (seepara. 3). The thread series symbols for the UN threadform are UNC, UNF, UNEF, or UN for only those sizesof the various series shown in Table 1 and UNS forany other intermediate and larger size diameter-pitchcombination having tolerances to unified formulation.The corresponding thread series symbols for the UNRthread form are UNRC, UNRF, UNREF, or UNR. Thesymbol UNRS corresponds to UNS. The thread classsymbols are 1A, 1B, 2A, 2B, 3A, or 3B, where the suffixesA and B relate to external and internal threads, respec-tively.

The basic method of designating a screw thread isused where the standard tolerances or limits of sizebased on the standard length of engagement are applica-ble, as indicated in para. 5.

UNS threads and threads having special length ofengagement require certain additional information asshown in paras. 6.4 and 6.6.


Table 5 Thread Form Data

0.1875H[Note (1)] 0.2500H

0.1250H [Note (1)]Truncation of[Note (1)]UNR Design External

Basic Flat at Flat at Truncation of Profile Thread Root0.1667HInternal Internal Internal External andH [Note (1)]

Thread Crest, Thread Root Thread Root Thread Root Truncation of[Note (1)]and External and External and External External and Half InternalUN Thread Thread Crest, Height of Thread Crest, Thread Root Addendum of Thread Crest,Root, Frs p Frn p Fcs p Sharp frn p fes p Full Radius, External frs p fcn p

Threads/ Fcn p P/4 p P/8 p V-Thread p 0.10825318P Max., rrs p Thread, Srs p 0.21650635Pin. Pitch, P 0.25000000P 0.12500000P 0.86602540P [Note (2)] 0.14433757P 0.16237976P [Note (3)]

1 2 3 4 5 6 7 8 9

80 0.01250000 0.003125 0.001563 0.010825 0.001353 0.001804 0.002030 0.00270672 0.01388889 0.003472 0.001736 0.012028 0.001504 0.002005 0.002255 0.00300764 0.01562500 0.003906 0.001953 0.013532 0.001691 0.002255 0.002537 0.00338356 0.01785714 0.004464 0.002232 0.015465 0.001933 0.002577 0.002900 0.00386648 0.02083333 0.005208 0.002604 0.018042 0.002255 0.003007 0.003383 0.00451144 0.02272727 0.005682 0.002841 0.019682 0.002460 0.003280 0.003690 0.00492140 0.02500000 0.006250 0.003125 0.021651 0.002706 0.003608 0.004059 0.005413

36 0.02777778 0.006944 0.003472 0.024056 0.003007 0.004009 0.004511 0.00601432 0.03125000 0.007813 0.003906 0.027063 0.003383 0.004511 0.005074 0.00676628 0.03571429 0.008929 0.004464 0.030929 0.003866 0.005155 0.005799 0.00773227 0.03703704 0.009259 0.004630 0.032075 0.004009 0.005346 0.006014 0.00801924 0.04166667 0.010417 0.005208 0.036084 0.004511 0.006014 0.006766 0.00902120 0.05000000 0.012500 0.006250 0.043301 0.005413 0.007217 0.008119 0.01082518 0.05555556 0.013889 0.006944 0.048113 0.006014 0.008019 0.009021 0.012028

16 0.06250000 0.015625 0.007813 0.054127 0.006766 0.009021 0.010149 0.01353214 0.07142857 0.017857 0.008929 0.061859 0.007732 0.010310 0.011599 0.01546513 0.07692308 0.019231 0.009615 0.066617 0.008327 0.011103 0.012491 0.01665412 0.08333333 0.020833 0.010417 0.072169 0.009021 0.012028 0.013532 0.01804211.5 0.08695652 0.021739 0.010870 0.075307 0.009413 0.012551 0.014120 0.01882711 0.09090909 0.022727 0.011364 0.078730 0.009841 0.013122 0.014762 0.01968210 0.10000000 0.025000 0.012500 0.086603 0.010825 0.014434 0.016238 0.021651

9 0.11111111 0.027778 0.013889 0.096225 0.012028 0.016038 0.018042 0.0240568 0.12500000 0.031250 0.015625 0.108253 0.013532 0.018042 0.020297 0.0270637 0.14285714 0.035714 0.017857 0.123718 0.015465 0.020620 0.023197 0.0309296 0.16666667 0.041667 0.020833 0.144338 0.018042 0.024056 0.027063 0.0360845 0.20000000 0.050000 0.025000 0.173205 0.021651 0.028868 0.032476 0.0433014.5 0.22222222 0.055556 0.027778 0.192450 0.024056 0.032075 0.036084 0.0481134 0.25000000 0.062500 0.031250 0.216506 0.027063 0.036084 0.040595 0.054127

59




Table 5 Thread Form Data (Cont’d)

0.625H[Note (1)]

Height of 0.9167HInternal [Note (1)]

Thread, UN0.375H 0.7500H 1.2500HExternal Difference[Note (1)] 0.6875H [Note (1)] [Note (1)] 1.3750H

Thread, and Between Max.[Note (1)] [Note (1)]Addendum of Depth of Twice the Major and Double Height

External Thread Height External Pitch of Internal Double HeightThread, Engagement, of UNR Thread Diameters of Thread and of External 0.5000Hhas p hs p hn p External Addendum, Internal External UN UNR Thread, [Note (1)]

Threads/ 0.32475953P he p Thread, hs p hb p 2has p Thread p Thread, 2hn p 2hs pin. [Note (4)] 0.54126588P 0.59539247P 0.64951905P 0.79385662P 1.08253175P 1.19078493P 0.43301270P

1 10 11 12 13 14 15 16 17

80 0.004059 0.006766 0.007442 0.008119 0.009923 0.013532 0.014885 0.00541372 0.004511 0.007518 0.008269 0.009021 0.011026 0.015035 0.016539 0.00601464 0.005074 0.008457 0.009303 0.010149 0.012404 0.016915 0.018606 0.00676656 0.005799 0.009665 0.010632 0.011599 0.014176 0.019331 0.021264 0.00773248 0.006766 0.011276 0.012404 0.013532 0.016539 0.022553 0.024808 0.00902144 0.007381 0.012301 0.013532 0.014762 0.018042 0.024603 0.027063 0.00984140 0.008119 0.013532 0.014885 0.016238 0.019846 0.027063 0.029770 0.010825

36 0.009021 0.015035 0.016539 0.018042 0.022052 0.030070 0.033077 0.01202832 0.010149 0.016915 0.018606 0.020297 0.024808 0.033829 0.037212 0.01353228 0.011599 0.019331 0.021264 0.023197 0.028352 0.038662 0.042528 0.01546527 0.012028 0.020047 0.022052 0.024056 0.029402 0.040094 0.044103 0.01603824 0.013532 0.022553 0.024808 0.027063 0.033077 0.045105 0.049616 0.01804220 0.016238 0.027063 0.029770 0.032476 0.039693 0.054127 0.059539 0.02165118 0.018042 0.030070 0.033077 0.036084 0.044103 0.060141 0.066155 0.024056

16 0.020297 0.033829 0.037212 0.040595 0.049616 0.067658 0.074424 0.02706314 0.023197 0.038662 0.042528 0.046394 0.056704 0.077324 0.085056 0.03092913 0.024982 0.041636 0.045799 0.049963 0.061066 0.083272 0.091599 0.03330912 0.027063 0.045105 0.049616 0.054127 0.066155 0.090211 0.099232 0.03608411.5 0.028240 0.047067 0.051773 0.056480 0.069031 0.094133 0.103547 0.03765311 0.029524 0.049206 0.054127 0.059047 0.072169 0.098412 0.108253 0.03936510 0.032476 0.054127 0.059539 0.064952 0.079386 0.108253 0.119078 0.043301

9 0.036084 0.060141 0.066155 0.072169 0.088206 0.120281 0.132309 0.0481138 0.040595 0.067658 0.074424 0.081190 0.099232 0.135316 0.148848 0.0541277 0.046394 0.077324 0.085056 0.092788 0.113408 0.154647 0.170112 0.0618596 0.054127 0.090211 0.099232 0.108253 0.132309 0.180422 0.198464 0.0721695 0.064952 0.108253 0.119078 0.129904 0.158771 0.216506 0.238157 0.0866034.5 0.072169 0.120281 0.132309 0.144338 0.176413 0.240563 0.264619 0.0962254 0.081190 0.135316 0.148848 0.162380 0.198464 0.270633 0.297696 0.108253

GENERAL NOTES:(a) All dimensions are in inches.(b) All thread calculations are to be performed using a function of pitch (P); the use of thread height (H) is for reference

only as stated in ASME B1.30.

NOTES:(1) The thread values based on a function of height “H” are used for reference only.(2) The values tabulated in column 6 also pertain to the minimum root radius of UNR screw threads. See paras. 2.3.1 and

2.3.1(a).(3) han p fcn p 0.25H p 0.21650635P(4) hdn p has p 0.375H p 0.32475953P

60


Nominal size (fractional diameter or screwnumber, the decimal equivalant of eitherbeing optional)

Number of threads per in.Thread form and series (see dimensional

tables)Thread class symbol (see para. 4)

1⁄4 – 20 UNC – 2A or 0.250 – 20 UNC – 2A (21)10 – 32 UNF – 2A or 0.190 – 32 UNF – 2A (22)7⁄16 – 20 UNRF – 2A or 0.4375 – 20 UNRF – 2A (23)7⁄16 – 20 UNF – 2A or 0.4375 – 20 UNF – 2A (21)2 – 12 UN – 2A or 2.000 – 12 UN – 2A (23)

Thread gaging system per ASME B1.3

NOTE: Thread acceptability gaging system requirement of ASMEB1.3 may be added to the thread size designation as noted aboveor as specified in pertinent documentation, such as drawing orprocurement document.

6.2 Method of Designating Coated Threads

Specification on drawings of the before and after coat-ing dimensions for screw threads is sometimes dictatedby an engineering or production consideration that thesize before and after coating be controlled. This resultsfrom coated screw threads having two stages of design,the before coating stage and the after coating stage. Thethreaded product may be produced by a supplier andcoated by a user. In this case, it is necessary that aclear understanding of the coating requirements and theallowance for coating buildup be agreed upon by bothsupplier and user (see para. 7).

The before coating (plating) dimensions have a defi-nite bearing on the strength of the screw threads. Thebefore coating stage is, therefore, decidedly an engi-neering consideration; it is also a production consider-ation in requiring that proper allowance be made for thespecified coating thickness. The finished parts should beof a size after coating that will allow them to be assem-bled with their coating components as intended.

Recommended methods for designating coatedthread under various conditions are described inpara. 6.2.1.

6.2.1 For coated (or plated) Class 2A externalthreads, the basic (max.) major and basic (max.) pitchdiameters shall be given, preceded by the words AFTERCOATING. The major and pitch diameter limits of sizebefore coating shall also be given, preceded by the wordsBEFORE COATING.EXAMPLE:

3⁄4 – 10 UNC – 2A (21)

After Coating

Max. major diameter 0.7500� Values shown fromMax. PD 0.6850 Table 2 for Class 3A

Before Coating

Major diameter 0.7482 – 0.7353� Values shown fromPD 0.6832 – 0.6773 Table 2 for Class 2A

61

Threads accepted to Class 2A limits before coatingare accepted after coating by basic size Class 3A GOthread gages. The allowance given in the dimensionaltables for Class 2A thread is sufficient to allow for alimited amount of coating as described in para. 7. How-ever, if a greater coating thickness is required, it willbe necessary to calculate the before coating limits inaccordance with para. 7.

6.2.2 For coated (or plated) Class 3A externalthreads, the maximum major and maximum pitch diam-eters may optionally be given, preceded by the wordsAFTER COATING, thereby indicating that the threadbefore coating must have special provisions to allow forcoating thickness. The major and pitch diameter limitsof size before coating (calculated in accordance withpara. 7 shall be given, followed by the letters SPL (spe-cial) and preceded by the words BEFORE COATING.

EXAMPLE: Thickness of coating 0.0002 in. to 0.0003 in.1⁄4 – 28 UNF-3A (21)

After Coating

Max. major diameter 0.2500� OptionalMax. PD 0.2268 Information

Before Coating

Major diameter 0.2494 – 0.2431 SPLPD 0.2256 – 0.2235 SPL

6.2.3 For coated (or plated) Class 1A externalthreads, the maximum major and maximum pitch diam-eters may optionally be given, preceded by the wordsAFTER COATING, thereby indicating that the threadbefore coating must have special provisions to allow forcoating thickness. The major and pitch diameter limitsof size before coating (calculated in accordance withpara. 7 shall be given, followed by the letters SPL (spe-cial) and preceded by the words BEFORE COATING.

EXAMPLE: Thickness of coating 0.0002 in. to 0.0003 in.1⁄4 – 20 UNC-1A (21)

After Coating

Max. major diameter 0.2489� OptionalMax. PD 0.2164 Information

Before Coating

Major diameter 0.2483 – 0.2363 SPLPD 0.2152 – 0.2100 SPL

6.2.4 Where an allowance is required to accommo-date coating (or plating) on Class 1B, 2B, or 3B internalthreads, the minimum minor and minimum pitch diam-eters may optionally be given, preceded by the wordsAFTER COATING. The minor and pitch diameter limitsof size before coating (calculated in accordance withpara. 7 shall be given, followed by the letters SPL (spe-cial) and preceded by the words BEFORE COATING.




EXAMPLES: Thickness of coating 0.0002 in. to 0.0003 in.

(a) 1⁄4 – 20 UNC-1B (21)

After Coating

Min. minor diameter 0.196� OptionalMin. PD 0.2175 Information

Before Coating

Minor diameter 0.197 – 0.207 SPLPD 0.2187 – 0.2256 SPL

(b) 3⁄4 – 10 UNC-2B (22)

After Coating


Before Coating


(c) 1⁄4 – 28 UNF-3B (23)

After Coating


Before Coating


NOTE: The after coating limits for all of the examplesabove are the minor and PD values in Table 2 for therespective class of thread.

6.3 Method of Designating Left-Hand Threads

Unless otherwise specified, threads are right hand; aleft-hand thread shall be designated LH as follows:

EXAMPLE: 1⁄4 – 20 UNC-3A-LH (21)

6.4 Method of Designating UNS Threads

UNS threads are special combinations of diameter andpitch with tolerance to unified formulation.

UNS threads have the basic form of designation setout above, supplemented always by the limits of size.

EXAMPLES:(a) 1⁄4 – 24 UNS-3A (21)

Major diameter 0.2500 – 0.2428PD 0.2229 – 0.2201Max. Minor diameter 0.205

(b) 0.495 – 20 UNS-3A (21)Major diameter 0.4950 – 0.4869PD 0.4625 – 0.4593Max. Minor diameter 0.441

(c) 1.200 – 10 UNS-2B (21)Minor diameter 1.092 – 1.113PD 1.1350 – 1.1432Min. Major diameter 1.200

62

6.5 Designations for Other Threads

Threads having tolerances that do not conform to uni-fied formulation and threads having multiple start orlead, or special form, also require additional considera-tions in the thread designation. The recommended meth-ods of designating these threads are described in paras.6.5.1 through 6.5.3.

6.5.1 Method of Designating Threads Having Toler-ances Not to Unified Formulation. If a standard seriesthread is altered in any respect other than revised pitchdiameter limits for a special length of engagement, themodification of crests, or the adjustment of the limitsof size to accommodate coating, as shown above, it isdesignated in accordance with the following:

EXAMPLES:(a) 7⁄16 – 24 Unified Form SPL-EXT (22)

Major diameter 0.4340 – 0.4280 SPLPD 0.4065 – 0.4025 SPLMax. Minor diameter 0.3889LE 0.38

(b) 1⁄2 – 13 Unified Form SPL-INT (22)Minor diameter 0.424 – 0.434 SPLPD 0.4500 – 0.4580 SPLMin. Major diameter 0.5000LE 0.50

6.5.2 Method of Designating Multiple Start Threads.If a thread is required with a multiple start or lead, itis designated by specifying in sequence the nominalsize, pitch (in decimals or threads per inch), and lead (indecimals or fractions), number of starts in parenthesis,thread series, class, and gaging system in parenthesis ifrequired to the following examples:

EXAMPLES:(a) 3⁄4 – 0.0625P – 0.1875L (3 STARTS) UNF SPL-EXT (23)

Major diameter 0.7485 – 0.7391PD 0.7079 – 0.7003 SPLMax. Minor diameter 0.6808LE 0.75

(b) 3⁄4 – 16 – 0.1875L (3 STARTS) UNF-2A (21)

6.5.3 Method of Designating Special Form Threads.If a thread for design consideration requires a variationfrom unified standard thread contour and is not coveredby another recognized standard, such as when the detailof the root differs from that for the standard thread form,the designation shall not include either the letters “UN”or the word “UNIFIED”, but shall be as follows:

EXAMPLE:7⁄8 – 18 SPL 60 deg Form-EXT (22)Major diameter 0.8750 – 0.8668PD 0.8384 – 0.8343Max. Minor diameter 0.8068LE 0.69


6.6 Method of Designating Threads Having SpecialLength of Engagement

In the assembly of threads in mating parts, the lengthof engagement varies according to the design require-ments. It should be noted that the length of engagementis not necessarily the same as the full thread lengthprovided on the part, but is the length of assembledthread in the mating parts.

Where a standard series thread has a special length ofengagement differing from that for which the standardpitch diameter tolerances are applicable as indicated inpara. 5, the thread class symbol is qualified by the addi-tion of the letters SE (special engagement) precedingthe class symbol. The specification of the special pitchdiameter limits of size and the length of engagementLE, rounded to a two place decimal, are a requirement.

EXAMPLES:(a) 1⁄2 – 13 UNC-SE2A (23)

PD 0.4485 – 0.4423LE 1.00

(b) 1⁄4 – 24 UNS-SE3A (23)Major diameter 0.2500 – 0.2428PD 0.2229 – 0.2194LE 0.88

6.6.1 In some cases where greater than standardlength of engagement is required, it is desirable to usestandard externally threaded parts with tolerancesbased on standard length of engagement. For example,in the case of a standard bolt assembled into a tappedhole in aluminum, the designation of the bolt threadwill conform to that of a thread for a standard lengthof engagement.

The designation for the tapped hole thread shouldinclude the allowance in the basic size, the pitch diame-ter limits of size, and the length of gage, in addition tothe information normally given. See para. 5.3.1(b).

EXAMPLE: Requiring use of 1.00 long GO thread and GO plaingages.

0.5025 – 13 UNS-SE2B (21)Minor diameter 0.420 – 0.437PD 0.4525 – 0.4606LG 1.00

Similarly, where greater than standard length ofengagement is required, it is desirable to use standardinternally threaded parts with tolerances based on stan-dard length of engagement. Therefore, the externalthread is provided with an added allowance. See para.5.3.1(c).

The designation for the external thread should includethe added allowance in the basic size, the pitch diameterlimits of size, and the length of gage, in addition to theinformation normally given.

63

EXAMPLE: Requiring use of 0.88 long GO thread and GO plaingages.

0.3725 – 24 UNS-SE2A (21)Major diameter 0.3714 – 0.3642PD 0.3443 – 0.3396LG 0.88

6.6.2 When a long length of engagement is requiredand standard length GO thread and GO plain gages areto be used, the thread designation should indicate thethread modifications and a standard gage length, LGStd. See para. 5.3.2.

EXAMPLES: With additional allowance indicating use of standardlength GO thread and GO plain gages.(a) 0.5058 – 13 UNS-2B (22)

Minor diameter 0.423 – 0.440PD 0.4558 – 0.4623LG Std.

(b) 0.3706 – 24 UNS-2A (22)Major diameter 0.3695 – 0.3623PD 0.3424 – 0.3386LG Std.

6.6.3 For applications of long length of engagementof mating parts involving very high strength materials,increases in tolerances based on standard length ofengagement may be detrimental. In these cases, the toler-ances based on the standard length of engagement maybe applied to increased length of engagement threads.This requires the GO thread gages to have a speciallength equal to the length of engagement as specified.

The designations for restricted applications should bequalified with the abbreviation SPL (special) as shownin the examples below. See para. 5.3.1(a)

EXAMPLES: Requiring use of 1.00 long GO thread and GOplain gages(a) 0.500 – 20 UNF-3A SPL (21)

LG 1.00 SPL

(b) 0.500 – 20 UNF-3B SPL (21)LG 1.00 SPL

NOTE: In drawings, tolerances tabulated for the standard lengthof engagement in ASME B1.1 shall apply over the full length ofengagement.

6.7 Method of Designating Threads Having ModifiedCrests

It is occasionally necessary to modify the limits of sizeof the major diameter of an external thread or the minordiameter of an internal thread within the maximum-material limits established for standard series and spe-cial threads in order to fit a specific purpose, but withoutchange in class of thread or pitch diameter limits. (Itshould be noted that standard pitch diameter gages maybe used to accept such threads.) Such threads shall bespecified with the established thread designation, fol-lowed by a statement of the modified diameter limitsand the designation MOD. This practice also applies tomodifications of internal thread minor diametersdescribed in para. 5.6.1.




EXAMPLES:(a) 3⁄8 – 24 UNF-3A MOD (21)

Major diameter 0.3720 – 0.3648 MOD(b) 11⁄2 – 10 UNS-3B MOD (21)

Minor diameter 1.398 – 1.409 MODPD 1.4350 – 1.4412Min. major diameter 1.500

7 DIMENSIONAL ACCOMMODATION OF COATINGOR PLATING FOR 60-deg THREADS

7.1 Introduction

It is not within the scope of this Standard to makerecommendations for thickness of, or to specify limitsfor, coatings. However, it will aid mechanical inter-changeability if certain principles are followed whereverconditions permit. The guidelines in paras. 7.4, 7.5, and7.6 should be helpful in determining the amount anddirection of the alterations to establish applicable limitsof size before coating threads with a 60 deg includedangle. Some commonly used and firmly established pro-cesses for heavy coatings, such as hot dip galvanizing,do not fall within the scope of this paragraph. Heavycoating, for purposes of this standard, is defined as acoating thickness greater than 0.25 times the thread’sallowance.

NOTE: The term coating refers to one or more applications ofadditive material to threads, including, but not limited to, electro-plated deposits, dip-spin applied materials, and mechanicallyapplied platings. It does not include soft or liquid lubricants thatare readily displaced in assembly and gaging.

This Standard specifies limits of size that pertainwhether threads are coated or uncoated. Only in Class2A threads is the allowance available to accommodatecoatings. Thus, in all classes of internal threads and inall Classes 1A and 3A external threads, limits of sizemust be adjusted before plating to provide suitable pro-vision for the desired coating.

7.2 Material Limits for Coated Threads

Unless otherwise specified, size limits for standardexternal thread Class 2A apply prior to coating. Theexternal thread allowance may thus be used to accom-modate the coating thickness on coated parts, providedthat the maximum coating thickness is no more thanone-fourth of the allowance (see Fig. 4). Thus, the threadafter coating is subject to acceptance using a basic Class3A GO thread gage and a Class 2A thread gage for eitherminimum material or NOT GO. Where external threadhas no allowance, or allowance must be maintained aftercoating, and for standard internal threads, sufficientallowance must be provided prior to coating to ensurethat finished product threads do not exceed the maxi-mum-material limits specified. For thread Class 3A,Class 2A allowances should be applied whenever possi-ble in accordance with calculations in para. 5.

64

7.3 Dimensional Effects of Coating

7.3.1 On a cylindrical surface, the effect of coatingis to change the diameter by twice the coating thickness,one coating thickness on each side of the cylinder. Ona screw thread, this would apply to the major and minordiameter.

7.3.2 Because the coating thickness is measured per-pendicular to the coated surface, while the pitch diame-ter is measured perpendicular to the thread axis, theeffect of a uniformly coated thread flank on the pitchdiameter is a change of four times the thickness of coat-ing on the flank (see Fig. 4). The diameters of externalthreads before coating will be smaller, while the diame-ters of internal threads before coating will be larger, thanthe coated diameters.

7.3.3 Most coatings and platings do not apply uni-formly on threads (see Fig. 5). Different coating materialsand processes have different application characteristics.The threaded part’s overall length and other configura-tion characteristics also affect the way the coatings buildup on the threads. Paragraphs 7.4, 7.5, and 7.6 providegeneral guidelines for calculating precoating thread sizeto allow for coating buildup while preventing interfer-ence in assembly. The exact precoating thread size fora given part with a given type of coating will frequentlyhave to be developed by the producer experimentally.

7.4 External Thread With Allowance Available forCoating

7.4.1 Maximum and Minimum Coating ThicknessSpecified. The amount of the allowance on the pitchdiameter is sufficient if 4 times the maximum coatingthickness is equal to or less than the allowance tabulatedin Table 2 or calculated per formula in para. 5.8.1(a).

7.4.2 Only Nominal or Minimum Coating ThicknessSpecified. If no thickness tolerance is given, it is recom-mended that a tolerance of plus 50% of the nominal orminimum thickness be assumed. Then the amount ofthe allowance on the pitch diameter is sufficient if 6times the specified coating thickness is equal to or lessthan the allowance tabulated in Table 2 or calculatedper formula in para. 5.8.1(a).

7.5 External Thread With No Allowance for Coating

7.5.1 Maximum and Minimum Coating ThicknessSpecified. To determine before coating gaging limitsdecrease

(a) the maximum pitch diameter by 4 times the maxi-mum coating thickness

(b) the minimum pitch diameter by 4 times the mini-mum coating thickness

(c) the maximum major diameter by 2 times the maxi-mum coating


Pitch diameter of screw after coating

Pitch diameter of screw before coating

Thread axis

0.5 P(ref.)

0.5 P(ref.)

Enlarged View

0.5a

t

ta

0.25a = t and a = 4t or the pitch diameter of a 60 deg thread changes four times the thickness of coating

==

thickness of coatingpitch diameter change due to coating

Sine 30 deg (in small triangle above) = = 0.5t0.5a

30 deg

Fig. 4 Ratio of Pitch Diameter Change to Thickness of Coating on 60-deg Threads

(d) the minimum major diameter by 2 times the mini-mum coating thickness

EXAMPLE: 3⁄8 – 16 UNC-2A (21) AFTER COATINGCoating thickness 0.0002 – 0.0003 in.

To determine the before coating maximum materialsizes, decrease the maximum pitch diameter of 0.3331 in.by 0.0012 in. (4 � 0.0003) to 0.3319 in., and the maximummajor diameter of 0.3737 in. by 0.0006 in. (2 � 0.0003)to 0.3731 in. For the before coating minimum sizes,decrease the minimum pitch diameter of 0.3287 in. by

65

0.0008 in. (4 � 0.0002) to 0.3279 in., and the minimummajor diameter of 0.3643 in. by 0.0004 in. (2 � 0.0002)to 0.3639 in. The before coating sizes should be includedin the thread designation (see para. 6.2.1).

7.5.2 Only Nominal or Minimum Coating ThicknessSpecified. If no coating thickness tolerance is given, itis recommended that a tolerance of plus 50% of thenominal or minimum thickness be assumed. Then, todetermine before coating gaging limits for a coatedthread, decrease




The effects of electroplating on the functional diameter

Enlarged View

GENERAL NOTE: Electrodeposited coatings build up more heavily at sharp corners; is greater at the extreme ends andedges; and is least in the center and recessed areas.

Fig. 5 Effect of Electrodeposited Coatings on 60-deg External Threads

(a) the maximum pitch diameter by 6 times the coat-ing thickness

(b) the minimum pitch diameter by 4 times the coat-ing thickness

(c) the maximum major diameter by 3 times the coat-ing thickness

(d) the minimum major diameter by 2 times the coat-ing thickness

EXAMPLE: 1⁄2 – 13 UNC-3A (22)Coating thickness 0.0004 in.

Since the allowance for Class 2A thread is 0.0015 in.,the nominal or minimum coating thickness that may beapplied is equal to 0.0015 in. divided by 6, or 0.00025 in.(the maximum thickness of coating that may be appliedis equal to 0.0015 divided by 4 or 0.0038 in.). This is notsufficient for the required nominal or minimum coatingof 0.0004 in. specified, so additional adjustments to thebefore coating pitch and major diameters must be made.

To determine the before coating maximum materialsizes, decrease the maximum pitch diameter of 0.4500 in.by 0.0024 in. (6 � 0.0004) to 0.4476 in., and the maximummajor diameter of 0.5000 in. by 0.0012 in. (3 � 0.0004)to 0.4988 in. For the before coating minimum sizes,decrease the minimum pitch diameter of 0.4463 in. by0.0016 in. (4 � 0.0004) to 0.4447 in., and the minimummajor diameter of 0.4891 in. by 0.0008 in. (2 � 0.0004)to 0.4883 in. The before coating sizes should be includedin the thread designation (see para. 6.2.1).

66

7.5.3 Adjusted Size Limits. It should be noted in thepreceding examples that the before coating materiallimit tolerances are less than the tolerances after coating.This is because the coating tolerance consumes some ofthe product tolerance. In some instances, there may beinsufficient pitch diameter tolerance available in thebefore coating condition, so that additional adjustmentsand controls will be necessary.

7.5.4 Strength. On small thread sizes (0.190 in. andsmaller) there is a possibility that coating thicknessadjustments will cause base material (minimum) condi-tions that may significantly affect strength of externallythreaded parts. Limitations on coating thickness, or partredesign, may be necessary.

7.6 Internal Threads

Standard internal threads provide no allowance forcoating thickness. To determine before coating gaginglimits for a coated thread, increase

(a) the minimum pitch diameter by 4 times the maxi-mum coating thickness, if specified, or by 6 times theminimum or nominal coating thickness, if not specified

(b) the maximum pitch diameter by 4 times the mini-mum or nominal coating thickness

(c) the minimum minor diameter by 2 times the maxi-mum coating thickness, if specified, or by 3 times theminimum or nominal coating thickness, if not specified

(d) the maximum minor diameter by 2 times the mini-mum or nominal coating thickness


7.7 Electrodeposited Coatings

Electroplated coatings do not cover threads uniformly.Deposits build up more on thread crests than on threadflanks and coating thickness is greater on lead end of athread than on threads in the center of a part. The guide-lines for calculating precoating thread sizes for uni-formly coated threads can be used as a starting placein determining the precoating thread sizes on a givenpart, but the exact sizes for any given part may have tobe determined by trial and error experimentation.

One of the effects of electrodeposited coatings notapplying uniformly is that the functional diameter ofan external thread will generally increase by a greatermagnitude than the increase of the pitch diameter on agiven part. Depending on an externally threaded part’sconfiguration an electrodeposited coating of 0.0001 in.on a thread flank will probably result in a growth ofthe pitch diameter of approximately 0.0004 in., but thefunctional diameter may change by as much as 0.0006 in.or more. In the case of internally threaded parts, elec-trodeposited coatings cause the pitch diameter and func-tional diameter to decrease in size, with the pitchdiameter decreasing less than the functional diameteron a given part.

Another effect of the nonuniform buildup of electro-deposited coatings is that the coating thickness on thelead end of a thread is commonly greater than the thick-ness on the threads in the center of the part. This resultsin the pitch diameter and functional diameter of a threadto be considerably larger on the end of the part thantheir comparable measurements away from the end. Thelonger the part, in the case of external threads, or thethicker the part, in the case of internal threads, thegreater these differences tend to be. The part producerand the plater can not control this phenomenon. It is thenature of electrodeposited coatings on threaded parts. Itis conceivable that a part’s dimensions can measurewithin limits on the lead threads and be beyond theirlimits on the threads away from the lead threads.

7.8 Other Considerations

It is essential to adequately review all possibilitiesand consider limitations in the threading and coatingproduction processes before finalizing the coating pro-cess and the allowance required to accommodate thecoating. A no allowance thread after coating shall nottransgress the basic profile, and is therefore subject toacceptance using a basic Class 3A, 1B, 2B, or 3B size GOthread gage.

8 STANDARD SERIES THREADS (UN/UNR) ANDLIMITS OF SIZE FOR STANDARD SERIES ANDUNS/UNRS SERIES THREADS

8.1 Standard SeriesThe standard series for unified inch screw threads is

listed in Table 1. Although the designations shown are

67

for the UN thread form, UNR designations may be usedin all cases.

8.2 Limits of Size

The limits of size are defined by the design profileat its maximum-material condition and the minimumprofile at the minimum-material condition. The limitsare specified as diameters (major diameter, minor diam-eter, pitch diameter), and the practical interpretation ofthese limits on a three-dimensional threaded productdepends on the method of inspection/evaluation. Thesedimensions serve as a basis for measurement and gagingof the thread, but the methods, techniques, and equip-ment used for thread evaluation establish the degree ofthread conformance to the tabulated dimensions. Cur-rent techniques for measuring and gaging do not verifyexact conformance of a thread to its specified maximumand minimum envelope. See ASME B1.3 for gaging sys-tems for dimensional acceptability.

8.2.1 Limits of size for the majority of the standardseries are shown in Tables 2 and E-1. Until this Standardis revised to require the calculated and rounded valuesper ASME B1.30 shown in Table 2, both these and thevalues in Table E-1 will be equally acceptable. It is recom-mended that all users prepare for the eventual adoptionof only the values in Table 2.

Omissions are the secondary size range in the 4-UNseries, and all sizes over 6 in. refer to Table 1 for a listof secondary sizes.

8.2.2 Limits of size not given may be calculatedfrom the formulas given in the following paragraphs.Formulas and symbols for thread form are given inpara. 10.

8.3 Formulas for Limits of Size

These formulas were used to calculate the valuesshown in Table 2 for standard series. The followingsymbols are used in the equations. (See Figs. 1 and 6.)

D bsc p basic major (nominal) diameterD1 bsc p basic minor diameter (D − 2hn) (see Tables 6

through 16)D2 bsc p basic pitch diameter (D − hb) (see Tables 6

through 16)d3 p UNR series design minor diameter [d1 − (H/

8)] (see Tables 6 through 16)has p screw addendum height (see Table 5)hb p 2has (see Table 5)hn p height of internal thread (see Table 5)hs p height of external thread (see Table 5)P p pitch, in.

To obtain limits of size using the formulas, see Table5 for basic thread form data, para. 11 for basic dimen-sions, and para. 5 for formulas of allowance and toler-ance. For easy reference, outline guides for determining




limits of size of external and internal threads are givenin Tables 17A and 17B.

8.3.1 External Thread(a) Maximum Major Diameter (External Threads)

(1) For Classes 1A and 2A, d p basic major diame-ter, D bsc, minus allowance.

(2) For Class 3A, d p basic major diameter, D bsc.(b) Minimum Major Diameter (External Threads). For all

classes, equals maximum major diameter, minus majordiameter tolerance for respective class of thread.

(c) Maximum Pitch Diameter (External Threads)(1) For Classes 1A and 2A, d2 p basic pitch diame-

ter D2 bsc, minus allowance.(2) For Class 3A, d2 p basic pitch diameter D2 bsc.

(d) Minimum Pitch Diameter (External Threads). For allclasses, equals maximum pitch diameter, minus pitchdiameter tolerance for respective class of thread.

(e) Maximum Minor Diameter (External Threads). Indimensioning UN series external threads, the minordiameter is not specified. In practice, the minor diameteris satisfactory when accepted by a standard GO threadgage in accordance with ASME B1.2. When it is desirableto obtain minor diameter values for reference purposesand for UNR threads, they can be calculated as follows:

(1) For UN series threads, the formulas are:(a) for Classes 1A and 2A, d1 p basic minor diam-

eter D1 bsc, minus allowance(b) for Class 3A, d1 p basic minor diameter

D1 bsc(2) For UNR series threads, the formulas are:

(a) for Classes 1A and 2A, d3 p basic minor diam-eter D1 bsc, minus allowance, minus H/8

(b) or Class 3A, d3 p basic minor diameter D1 bsc,minus H/8

(f) Minimum Minor Diameter (External Threads). Whenit is desirable for design purposes to calculate the mini-mum diameter, it can be obtained for all classes by theformula: minimum pitch diameter minus 0.64951905P.

8.3.2 Internal Thread(a) Maximum Major Diameter (Internal Threads). In

dimensioning internal threads, the maximum majordiameter is not specified, being established by the crestof an unworn tool. In practice, the major diameter ofan internal thread is satisfactory when accepted by agage or gaging method that represents the maximum-material condition of an external thread that has noallowance.

(b) Minimum Major Diameter (Internal Threads), D bsc.For all classes, equals basic diameter D bsc.

(c) Minimum Pitch Diameter. For all classes, D2 bscequals basic pitch diameter D2 minimum.

(d) Maximum Pitch Diameter (Internal Threads). For allclasses, equals minimum pitch diameter D2 bsc, pluspitch diameter tolerance for respective class of thread.

68

(e) Minimum Minor Diameter (Internal Threads). For allclasses, D1 bsc equals minimum pitch diameter D2 mini-mum minus 0.43301122P, then rounded off to the nearest0.001 in. for sizes 0.138 in. and larger. For Class 3B, acipher is added to yield four decimal places.

(f) Maximum Minor Diameter (Internal Threads). Allclasses are calculated before rounding, then rounded forClasses 1B and 2B to the nearest 0.001 in. for sizes 0.138in. and larger. Class 3B values are rounded to four deci-mal places.

8.4 Example of Calculations From Formulas

Tables 18A and 18B are based on the practices forcalculating and rounding screw thread dimensions asspecified in ASME B1.30.

9 LEAD AND ANGLE TOLERANCES

9.1 Lead and Flank Angle Acceptance

Acceptance of lead and flank angles of product screwthreads shall be in accordance with the following. Also,these are factors contributing to visual identification ofgross defects in thread profile.

9.1.1 When Thread Gaging System 21 of ASME B1.3is specified, product thread lead (including helix) andflank angle variations are not considered as separateelements.

9.1.2 When Thread Gaging System 22 of ASME B1.3is specified, with the pitch diameter or thread-groovediameter inspection/evaluation required, the productthread lead (including helix) and flank angles shall beconsidered acceptable when the minimum-materialcharacteristic (pitch diameter or thread-groove diameterin Tables 1 and 2, columns C and D of ASME B1.3) andthe maximum-material characteristic (GO in Tables 1and 2, column A of ASME B1.3) are accepted by thegages specified for System 22, over the standard GOthread gage length.

When Thread Gaging System 22 is specified with NOTGO functional diameter combined with inspection/evaluation of lead and flank option, agreements mustbe reached between the purchaser and the supplier onlead and flank angle limits and method of evaluation.

9.1.3 When Thread Gaging System 23 of ASME B1.3is specified, product thread lead and flank angles shallbe acceptable if within the allowable variations specifiedin Tables 3 and 19, respectively. Also, the minimum-material characteristic (pitch diameter or thread-groovediameter in Tables 1 and 2, columns C and D of ASMEB1.3) and the maximum-material characteristic (GO inTables 1 and 2, column A of ASME B1.3) must beaccepted by the gages specified for System 23, over thestandard GO thread gage length.

Allowable variations in lead and flank angles are max-imum values. Maximum variation in these and pitch


diameter tolerance cannot be taken simultaneously (seeparas. 9.1.5 and 9.1.6).

9.1.4 When individual inspection/evaluation of lead(including helix) and flank angle variations are requiredin addition to thread gaging System 21 or 22 of ASMEB1.3, the allowable variations for these characteristicsshall be as specified in Tables 3 and 19.

9.1.5 For sizes not included in Tables 3 and 19, theallowable lead variation is equal to 0.57735 times one-half the pitch diameter tolerance. This is the lead varia-tion that causes a change in functional diameter equalto one-half the pitch diameter tolerance. The allowableflank half-angle variation in minutes of arc is equal to30 plus 1.875 times the number of threads per inch,rounded to the nearest 5 min.

9.1.6 For the requirements of paras. 9.1.4 and 9.1.5,lead variation values tabulated or calculated are themaximum variations from specified lead between anytwo points not farther apart than the length of the stan-dard GO thread gage. Flank angle variation values aremaximum variations from the basic 30 deg anglebetween thread flanks and perpendiculars to thethread axis.

10 FORMULAS AND SYMBOLS FOR THREAD FORM

10.1 Thread Form Formulas and Symbols

Formulas are given below; data are tabulated inTable 5.

The general symbols used are defined in Table 20 andapplication of the symbols is shown in Fig. 6.

(a) Included Angle of Thread

2� p 60 deg

(b) Half angle of thread

� p 30 deg

(c) Number of threads per inch (TPI) is 1/P Pitch ofthread.

P p 1/TPI

(d) Height of sharp V-thread (fundamental triangle)

H p 0.86602540P

(e) Height of UNR external thread, design form

hs p 0.59539247P p (11/16H)

(f) Height of internal thread and UN external thread

hs p hn p 0.54126588P p (5/8H)

(g) Height of thread engagement

hs p 0.54126588P p (5/8H)

69

(h) Flat at crest of external thread

Fcs p 0.12500000P p P/8

(i) Truncation of UN external thread crest

fcs p 0.10825318P p (H/8)

(j) Truncation of UNR external thread (for calculatingminor diameter values in tables)

Srs p 0.16237976P p (3/16H)

(k) Basic flat at crest of internal thread and root ofexternal thread

Frs p Fcn p 0.25000000P p P/4

(l) Truncation of internal thread crest

fcn p 0.21650635P p (H/4)

(m) Flat at root of internal thread

Frn p 0.12500000P p P/8

(n) Truncation of internal thread root

frn p 0.10825318P p (H/8)

(o) Addendum of external thread

has p 0.32475953P p (3/8H)

(p) Major diameter of external thread is d. Pitch diam-eter of external thread

d2 p d − 2has p d − 0.64951905P

(q) Minor diameter of UNR external thread

d3 p d − 2hs p 1.19078493P

(r) Minor diameter of UN external thread

d1 p d − 2hs p d − 1.08253175P

(s) Major diameter of internal thread is D. Pitch diam-eter of internal thread is D2. Minor diameter of internalthread:

D1 p D − 2hn p D − 1.08253175P




11 TABLES OF BASIC DIMENSIONS

11.1 Table Content

The basic dimensions tabulated in Tables 6 through 16include major diameter, pitch diameter, minor diameterof external threads, minor diameter of internal threads,

Lts

Ltn

LE

P

�2�1

Min

or

dia

m.

Leading flank

Following flankLeading flank

Following flank

Vanish thread

Complete thread [Note (1)]

Count pitches at crest

Start of first complete external thread

End of externally threaded fastener

HelixHelix angle

90 deg

es/2

he�d2

(360 deg)

Start of first complete thread

Vanish cone

Pit

ch d

iam

.

Maj

or

dia

m.

Lead angle

Lead“Unrolled ”pitch cylinder

Lead and Helix AnglesThread With an Allowance

Minimum internal thread

Maximum external thread

�

NOTE:(1) Portion of thread fully formed at crest and root.

Fig. 6 Application of General Thread Symbols (See Table 5)

70

lead angle, cross-sectional area at the minor diameter,and the tensile stress area.

11.2 Thread Series

Basic dimensions are given for each of the standardseries threads.


T

Root

d3 d2d2

d1

D2D1

D

d

dMw

srsfrs

Frs

hds

has

Fcs

fcn

hdn

frn

Frn

hn

Fcn

han

w

hs

Hrrs

scs

scn

Rrn

Rcn

srn

rcs

Maj

or

dia

m.

Pit

ch d

iam

.

Min

or

dia

m.

D1 D2 D3

Maj

or

dia

m.

Pit

ch d

iam

.

Min

or

dia

m.

Axis of external thread

External Thread

Pitch P

90 deg

90 deg

Flan

k

Flan

kPitch line

Pitch line

P/2

2

Root Root

Axis of internal thread

Internal Thread

Base

�

CrestCrest

Crest Crest

�

GENERAL NOTE: These diagrams are not intended to show standard thread forms, but only to illustrate the application ofsymbols.

Fig. 6 Application of General Thread Symbols (See Table 5) (Cont’d)

71




Table 6 Basic Dimensions for Coarse-Thread Series (UNC/UNRC)

UNR Design Section atLead AngleMinor Basic Minor Tensile

at BasicBasic Basic Diameter Minor Diameter Stress Area,PitchMajor Pitch External, Diameter at D − 2hb, sq in.

Diameter, �Nominal Size, Diameter, Threads/ Diameter, d3, in. Internal, sq in. [Notes (1),in. D, in. in. D2, in. (Ref.) D1, in. deg Min. [Note (1)] (2)]

1 (0.073) [Note (3)] 0.0730 64 0.0629 0.0544 0.0561 4 31 0.00218 0.002632 (0.086) 0.0860 56 0.0744 0.0648 0.0667 4 22 0.00310 0.003703 (0.099) [Note (3)] 0.0990 48 0.0855 0.0741 0.0764 4 26 0.00406 0.004874 (0.112) 0.1120 40 0.0958 0.0822 0.0849 4 45 0.00496 0.00604

5 (0.125) 0.1250 40 0.1088 0.0952 0.0979 4 11 0.00672 0.007966 (0.138) 0.1380 32 0.1177 0.1008 0.1042 4 50 0.00745 0.009098 (0.164) 0.1640 32 0.1437 0.1268 0.1302 3 58 0.01196 0.014010 (0.190) 0.1900 24 0.1629 0.1404 0.1449 4 39 0.01450 0.017512 (0.216) [Note (3)] 0.2160 24 0.1889 0.1664 0.1709 4 1 0.0206 0.0242

1⁄4 0.2500 20 0.2175 0.1905 0.1959 4 11 0.0269 0.03185⁄16 0.3125 18 0.2764 0.2464 0.2524 3 40 0.0454 0.05243⁄8 0.3750 16 0.3344 0.3005 0.3073 3 24 0.0678 0.07757⁄16 0.4375 14 0.3911 0.3525 0.3602 3 20 0.0933 0.10631⁄2 0.5000 13 0.4500 0.4084 0.4167 3 7 0.1257 0.1419

9⁄16 0.5625 12 0.5084 0.4633 0.4723 2 59 0.162 0.1825⁄8 0.6250 11 0.5660 0.5168 0.5266 2 56 0.202 0.2263⁄4 0.7500 10 0.6850 0.6309 0.6417 2 40 0.302 0.3347⁄8 0.8750 9 0.8028 0.7427 0.7547 2 31 0.419 0.462

1 1.0000 8 0.9188 0.8512 0.8647 2 29 0.551 0.60611⁄8 1.1250 7 1.0322 0.9549 0.9704 2 31 0.693 0.76311⁄4 1.2500 7 1.1572 1.0799 1.0954 2 15 0.890 0.96913⁄8 1.3750 6 1.2667 1.1766 1.1946 2 24 1.054 1.15511⁄2 1.5000 6 1.3917 1.3016 1.3196 2 11 1.294 1.405

13⁄4 1.7500 5 1.6201 1.5119 1.5335 2 15 1.74 1.902 2.0000 41⁄2 1.8557 1.7353 1.7594 2 11 2.30 2.5021⁄4 2.2500 41⁄2 2.1057 1.9853 2.0094 1 55 3.02 3.2521⁄2 2.5000 4 2.3376 2.2023 2.2294 1 57 3.72 4.0023⁄4 2.7500 4 2.5876 2.4523 2.4794 1 46 4.62 4.93

3 3.0000 4 2.8376 2.7023 2.7294 1 36 5.62 5.9731⁄4 3.2500 4 3.0876 2.9523 2.9794 1 29 6.72 7.1031⁄2 3.5000 4 3.3376 3.2023 3.2294 1 22 7.92 8.3333⁄4 3.7500 4 3.5876 3.4523 3.4794 1 16 9.21 9.664 4.0000 4 3.8376 3.7023 3.7294 1 11 10.61 11.08

NOTES:(1) For information only.(2) See formulas in Nonmandatory Appendix B, para. B-1.(3) Secondary sizes.

72


Table 7 Basic Dimensions for Fine-Thread Series (UNF/UNRF)

UNR DesignLead AngleMinor Basic Section at

at BasicBasic Diameter Minor Minor TensilePitchBasic Major Pitch External, Diameter Diameter at Stress Area,

Diameter, �Diameter, D, Threads/ Diameter, d3, in. Internal, D − 2hb, sq in. sq in.Nominal Size, in. in. in. D2, in. (Ref.) D1, in. deg Min. [Note (1)] [Notes (1), (2)]

0 (0.060) 0.0600 80 0.0519 0.0451 0.0465 4 23 0.00151 0.001801 (0.073) [Note (3)] 0.0730 72 0.0640 0.0565 0.0580 3 57 0.00237 0.002782 (0.086) 0.0860 64 0.0759 0.0674 0.0691 3 45 0.00339 0.003943 (0.099) [Note (3)] 0.0990 56 0.0874 0.0778 0.0797 3 43 0.00451 0.005234 (0.112) 0.1120 48 0.0985 0.0871 0.0894 3 51 0.00566 0.00661

5 (0.125) 0.1250 44 0.1102 0.0979 0.1004 3 45 0.00716 0.008306 (0.138) 0.1380 40 0.1218 0.1082 0.1109 3 44 0.00874 0.010158 (0.164) 0.1640 36 0.1460 0.1309 0.1339 3 28 0.01285 0.0147410 (0.190) 0.1900 32 0.1697 0.1528 0.1562 3 21 0.0175 0.020012 (0.216) [Note (3)] 0.2160 28 0.1928 0.1734 0.1773 3 22 0.0226 0.0258

1⁄4 0.2500 28 0.2268 0.2074 0.2113 2 52 0.0326 0.03645⁄16 0.3125 24 0.2854 0.2629 0.2674 2 40 0.0524 0.05803⁄8 0.3750 24 0.3479 0.3254 0.3299 2 11 0.0809 0.08787⁄16 0.4375 20 0.4050 0.3780 0.3834 2 15 0.1090 0.11871⁄2 0.5000 20 0.4675 0.4405 0.4459 1 57 0.1486 0.1599

9⁄16 0.5625 18 0.5264 0.4964 0.5024 1 55 0.189 0.2035⁄8 0.6250 18 0.5889 0.5589 0.5649 1 43 0.240 0.2563⁄4 0.7500 16 0.7094 0.6763 0.6823 1 36 0.351 0.3737⁄8 0.8750 14 0.8286 0.7900 0.7977 1 34 0.480 0.509

1 1.0000 12 0.9459 0.9001 0.9098 1 36 0.625 0.66311⁄8 1.1250 12 1.0709 1.0258 1.0348 1 25 0.812 0.85611⁄4 1.2500 12 1.1959 1.1508 1.1598 1 16 1.024 1.07313⁄8 1.3750 12 1.3209 1.2758 1.2848 1 9 1.260 1.31511⁄2 1.5000 12 1.4459 1.4008 1.4098 1 3 1.521 1.581

NOTES:(1) For information only.(2) See formulas in Nonmandatory Appendix B, para. B-1.(3) Secondary sizes.

73




Table 8 Basic Dimensions for Extra-Fine-Thread Series (UNEF/UNREF)


at BasicBasic Basic Diameter Minor Minor TensilePitchMajor Pitch External, Diameter Diameter at Stress Area,

Nominal Size, in. Diameter, �Diameter, Threads/ Diameter, d3, in. Internal, D − 2hb, sq in. sq in.Primary Secondary D, in. in. D2, in. (Ref.) D1, in. deg Min. [Note (1)] [Notes (1), (2)]

. . . 12 (0.216) 0.2160 32 0.1957 0.1788 0.1822 2 55 0.0242 0.02701⁄4 . . . 0.2500 32 0.2297 0.2128 0.2162 2 29 0.0344 0.03795⁄16 . . . 0.3125 32 0.2922 0.2753 0.2787 1 57 0.0581 0.06253⁄8 . . . 0.3750 32 0.3547 0.3378 0.3412 1 36 0.0878 0.09327⁄16 . . . 0.4375 28 0.4143 0.3949 0.3988 1 34 0.1201 0.1274

1⁄2 . . . 0.5000 28 0.4768 0.4574 0.4613 1 22 0.162 0.1709⁄16 . . . 0.5625 24 0.5354 0.5129 0.5174 1 25 0.203 0.2145⁄8 . . . 0.6250 24 0.5879 0.5754 0.5799 1 16 0.256 0.268

. . . 11⁄16 0.6875 24 0.6604 0.6379 0.6424 1 9 0.315 0.329

3⁄4 . . . 0.7500 20 0.7175 0.6905 0.6959 1 16 0.369 0.386. . . 13⁄16 0.8125 20 0.7800 0.7530 0.7584 1 10 0.439 0.458

7⁄8 . . . 0.8750 20 0.8425 0.8155 0.8209 1 5 0.515 0.536. . . 15⁄16 0.9375 20 0.9050 0.8780 0.8834 1 0 0.598 0.620

1 . . . 1.0000 20 0.9675 0.9405 0.9459 0 57 0.687 0.711. . . 11⁄16 1.0625 18 1.0264 0.9964 1.0024 0 59 0.770 0.799

11⁄8 . . . 1.1250 18 1.0889 1.0589 1.0649 0 56 0.871 0.901. . . 13⁄16 1.1875 18 1.1514 1.1214 1.1274 0 53 0.977 1.009

11⁄4 . . . 1.2500 18 1.2139 1.1839 1.1899 0 50 1.090 1.123. . . 15⁄16 1.3125 18 1.2764 1.2464 1.2524 0 48 1.208 1.244

13⁄8 . . . 1.3750 18 1.3389 1.3089 1.3149 0 45 1.333 1.370. . . 17⁄16 1.4375 18 1.4014 1.3714 1.3774 0 43 1.464 1.503

11⁄2 . . . 1.5000 18 1.4639 1.4339 1.4399 0 42 1.60 1.64. . . 19⁄16 1.5625 18 1.5264 1.4964 1.5024 0 40 1.74 1.79

15⁄8 . . . 1.6250 18 1.5889 1.5589 1.5649 0 38 1.89 1.94. . . 111⁄16 1.6875 18 1.6514 1.6214 1.6274 0 37 2.05 2.10

NOTES:(1) For information only.(2) See formulas in Nonmandatory Appendix B, para. B-1.

74


Table 9 Basic Dimensions for 4-Thread Series (4-UN/4-UNR)



Nominal Size, in. Diameter, �Diameter, Diameter, d3, in. Internal, D − 2hb, sq in. sq in.Primary Secondary D, in. D2, in. (Ref.) D1, in. deg Min. [Note (1)] [Notes (1), (2)]

21⁄2 [Note (3)] . . . 2.5000 2.3376 2.2023 2.2294 1 57 3.72 4.00. . . 25⁄8 2.6250 2.4626 2.3273 2.3544 1 51 4.16 4.45

23⁄4 [Note (3)] . . . 2.7500 2.5876 2.4523 2.4794 1 46 4.62 4.93. . . 27⁄8 2.8750 2.7126 2.5773 2.6044 1 41 5.11 5.44

3 [Note (3)] . . . 3.0000 2.8376 2.7023 2.7294 1 36 5.62 5.97. . . 31⁄8 3.1250 2.9626 2.8273 2.8544 1 32 6.16 6.52

31⁄4 [Note (3)] . . . 3.2500 3.0876 2.9523 2.9794 1 29 6.72 7.10. . . 33⁄8 3.3750 3.2126 3.0773 3.1044 1 25 7.31 7.70

31⁄2 [Note (3)] . . . 3.5000 3.3376 3.2023 3.2294 1 22 7.92 8.33. . . 35⁄8 3.6250 3.4626 3.3273 3.3544 1 19 8.55 9.00

33⁄4 [Note (3)] . . . 3.7500 3.5876 3.4523 3.4794 1 16 9.21 9.66. . . 37⁄8 3.8750 3.7126 3.5773 3.6044 1 14 9.90 10.36

4 [Note (3)] . . . 4.0000 3.8376 3.7023 3.7294 1 11 10.61 11.08. . . 41⁄8 4.1250 3.9626 3.8273 3.8544 1 9 11.34 11.83

41⁄4 . . . 4.2500 4.0876 3.9523 3.9794 1 7 12.10 12.61. . . 43⁄8 4.3750 4.2126 4.0773 4.1044 1 5 12.88 13.41

41⁄2 . . . 4.5000 4.3376 4.2023 4.2294 1 3 13.69 14.23. . . 45⁄8 4.6250 4.4626 4.3273 4.3544 1 1 14.52 15.1

43⁄4 . . . 4.7500 4.5876 4.4523 4.4794 1 0 15.4 15.9. . . 47⁄8 4.8750 4.7126 4.5773 4.6044 0 58 16.3 16.8

5 . . . 5.0000 4.8376 4.7023 4.7294 0 57 17.2 17.8. . . 51⁄8 5.1250 4.9626 4.8273 4.8544 0 55 18.1 18.7

51⁄4 . . . 5.2500 5.0876 4.9523 4.9794 0 54 19.1 19.7. . . 53⁄8 5.3750 5.2126 5.0773 5.1044 0 52 20.0 20.7

51⁄2 . . . 5.5000 5.3376 5.2023 5.2294 0 51 21.0 21.7. . . 55⁄8 5.6250 5.4626 5.3273 5.3544 0 50 22.1 22.7

53⁄4 . . . 5.7500 5.5876 5.4523 5.4794 0 49 23.1 23.8. . . 57⁄8 5.8750 5.7126 5.5773 5.6044 0 48 24.2 24.9

6 . . . 6.0000 5.8376 5.7023 5.7294 0 47 25.3 26.0

NOTES:(1) For information only.(2) See formulas in Nonmandatory Appendix B, para. B-1.(3) Standard sizes of the UNC series.

75








13⁄8 [Note (3)] . . . 1.3750 1.2667 1.1766 1.1946 2 24 1.054 1.155. . . 17⁄16 1.4375 1.3292 1.2391 1.2571 2 17 1.171 1.277

11⁄2 [Note (3)] . . . 1.5000 1.3917 1.3016 1.3196 2 11 1.294 1.405. . . 19⁄16 1.5625 1.4542 1.3641 1.3821 2 5 1.423 1.54

15⁄8 . . . 1.6250 1.5167 1.4271 1.4446 2 0 1.56 1.68. . . 111⁄16 1.6875 1.5792 1.4891 1.5071 1 55 1.70 1.83

13⁄4 . . . 1.7500 1.6417 1.5516 1.5696 1 51 1.85 1.98. . . 113⁄16 1.8125 1.7042 1.6141 1.6321 1 47 2.00 2.14

17⁄8 . . . 1.8750 1.7667 1.6766 1.6946 1 43 2.16 2.30. . . 115⁄16 1.9375 1.8292 1.7391 1.7571 1 40 2.33 2.47

2 . . . 2.0000 1.8917 1.8016 1.8196 1 36 2.50 2.65. . . 21⁄8 2.1250 2.0167 1.9266 1.9446 1 30 2.86 3.03

21⁄4 . . . 2.2500 2.1417 2.0516 2.0696 1 25 3.25 3.42. . . 23⁄8 2.3750 2.2667 2.1766 2.1946 1 20 3.66 3.85

21⁄2 . . . 2.5000 2.3917 2.3016 2.3196 1 16 4.10 4.29. . . 25⁄8 2.6250 2.5167 2.4266 2.4446 1 12 4.56 4.76

23⁄4 . . . 2.7500 2.6417 2.5516 2.5696 1 9 5.04 5.26. . . 27⁄8 2.8750 2.7667 2.6766 2.6946 1 6 5.55 5.78

3 . . . 3.0000 2.8917 2.8016 2.8196 1 3 6.09 6.33. . . 31⁄8 3.1250 3.0167 2.9266 2.9446 1 0 6.64 6.89

31⁄4 . . . 3.2500 3.1417 3.0516 3.0696 0 58 7.23 7.49. . . 33⁄8 3.3750 3.2667 3.1766 3.1946 0 56 7.84 8.11

31⁄2 . . . 3.5000 3.3917 3.3016 3.3196 0 54 8.47 8.75. . . 35⁄8 3.6250 3.5167 3.4266 3.4446 0 52 9.12 9.42

33⁄4 . . . 3.7500 3.6417 3.5516 3.5696 0 50 9.81 10.11. . . 37⁄8 3.8750 3.7667 3.6766 3.6946 0 48 10.51 10.83

4 . . . 4.0000 3.8917 3.8016 3.8196 0 47 11.24 11.57. . . 41⁄8 4.1250 4.0167 3.9266 3.9446 0 45 12.00 12.33

41⁄4 . . . 4.2500 4.1417 4.0516 4.0696 0 44 12.78 13.12. . . 43⁄8 4.3750 4.2667 4.1766 4.1946 0 43 13.58 13.94

41⁄2 . . . 4.5000 4.3917 4.3016 4.3196 0 42 14.41 14.78. . . 45⁄8 4.6250 4.5167 4.4266 4.4446 0 40 15.3 15.6

43⁄4 . . . 4.7500 4.6417 4.5516 4.5696 0 39 16.1 16.5. . . 47⁄8 4.8750 4.7667 4.6766 4.6946 0 38 17.0 17.5

5 . . . 5.0000 4.8917 4.8016 4.8196 0 37 18.0 18.4. . . 51⁄8 5.1250 5.0167 4.9266 4.9446 0 36 18.9 19.3

51⁄4 . . . 5.2500 5.1417 5.0516 5.0696 0 35 19.9 20.3. . . 53⁄8 5.3750 5.2667 5.1766 5.1946 0 35 20.9 21.3

51⁄2 . . . 5.5000 5.3917 5.3016 5.3196 0 34 21.9 22.4. . . 55⁄8 5.6250 5.5167 5.4266 5.4446 0 33 23.0 23.4

53⁄4 . . . 5.7500 5.6417 5.5516 5.5696 0 32 24.0 24.5. . . 57⁄8 5.8750 5.7667 5.6766 5.6946 0 32 25.1 25.6

6 . . . 6.0000 5.8917 5.8016 5.8196 0 31 26.3 26.8

NOTES:(1) For information only.(2) See formulas in Nonmandatory Appendix B, para. B-1.(3) Standard sizes of the UNC series.

76






1 [Note (3)] . . . 1.0000 0.9188 0.8512 0.8647 2 29 0.551 0.606. . . 11⁄16 1.0625 0.9813 0.9137 0.9272 2 19 0.636 0.695

11⁄8 . . . 1.1250 1.0438 0.9792 0.9897 2 11 0.728 0.790. . . 13⁄16 1.1875 1.1063 1.0387 1.0522 2 4 0.825 0.892

11⁄4 . . . 1.2500 1.1688 1.1012 1.1147 1 57 0.929 1.000. . . 15⁄16 1.3125 1.2313 1.1637 1.1772 1 51 1.039 1.114

13⁄8 . . . 1.3750 1.2938 1.2262 1.2397 1 46 1.155 1.233. . . 17⁄16 1.4375 1.3563 1.2887 1.3022 1 41 1.277 1.360

11⁄2 . . . 1.5000 1.4188 1.3512 1.3647 1 36 1.405 1.492. . . 19⁄16 1.5625 1.4813 1.4137 1.4272 1 32 1.54 1.63

15⁄8 . . . 1.6250 1.5438 1.4806 1.4897 1 29 1.68 1.78. . . 111⁄16 1.6875 1.6063 1.5387 1.5522 1 25 1.83 1.93

13⁄4 . . . 1.7500 1.6688 1.6012 1.6147 1 22 1.98 2.08. . . 113⁄16 1.8125 1.7313 1.6637 1.6772 1 19 2.14 2.25

17⁄8 . . . 1.8750 1.7938 1.7262 1.7397 1 16 2.30 2.41. . . 115⁄16 1.9375 1.8563 1.7887 1.8022 1 14 2.47 2.59

2 . . . 2.0000 1.9188 1.8512 1.8647 1 11 2.65 2.77. . . 21⁄8 2.1250 2.0438 1.9762 1.9897 1 7 3.03 3.15

21⁄4 . . . 2.2500 2.1688 2.1012 2.1147 1 3 3.42 3.56. . . 23⁄8 2.3750 2.2938 2.2262 2.2397 1 0 3.85 3.99

21⁄2 . . . 2.5000 2.4188 2.3512 2.3647 0 57 4.29 4.44. . . 25⁄8 2.6250 2.5438 2.4762 2.4897 0 54 4.76 4.92

23⁄4 . . . 2.7500 2.6688 2.6012 2.6147 0 51 5.26 5.43. . . 27⁄8 2.8750 2.7938 2.7262 2.7397 0 49 5.78 5.95

3 . . . 3.0000 2.9188 2.8512 2.8647 0 47 6.32 6.51. . . 31⁄8 3.1250 3.0438 2.9762 2.9897 0 45 6.89 7.08

31⁄4 . . . 3.2500 3.1688 3.1012 3.1147 0 43 7.49 7.69. . . 33⁄8 3.3750 3.2938 3.2262 3.2397 0 42 8.11 8.31

31⁄2 . . . 3.5000 3.4188 3.3512 3.3647 0 40 8.75 8.96. . . 35⁄8 3.6250 3.5438 3.4762 3.4897 0 39 9.42 9.64

33⁄4 . . . 3.7500 3.6688 3.6012 3.6147 0 37 10.11 10.34. . . 37⁄8 3.8750 3.7938 3.7262 3.7397 0 36 10.83 11.06

4 . . . 4.0000 3.9188 3.8512 3.8647 0 35 11.57 11.81. . . 41⁄8 4.1250 4.0438 3.9762 3.9897 0 34 12.34 12.59

41⁄4 . . . 4.2500 4.1688 4.1012 4.1147 0 33 13.12 13.38. . . 43⁄8 4.3750 4.2938 4.2262 4.2397 0 32 13.94 14.21

41⁄2 . . . 4.5000 4.4188 4.3512 4.3647 0 31 14.78 15.1. . . 45⁄8 4.6250 4.5438 4.4762 4.4897 0 30 15.6 15.9

43⁄4 . . . 4.7500 4.6688 4.6012 4.6147 0 29 16.5 16.8. . . 47⁄8 4.8750 4.7938 4.7262 4.7397 0 29 17.4 17.7

5 . . . 5.0000 4.9188 4.8512 4.8647 0 28 18.4 18.7. . . 51⁄8 5.1250 5.0438 4.9762 4.9897 0 27 19.3 19.7

51⁄4 . . . 5.2500 5.1688 5.1012 5.1147 0 26 20.3 20.7. . . 53⁄8 5.3750 5.2938 5.2262 5.2397 0 26 21.3 21.7

77




Table 11 Basic Dimensions for 8-Thread Series (8-UN/8-UNR) (Cont’d)




51⁄2 . . . 5.5000 5.4188 5.3512 5.3647 0 25 22.4 22.7. . . 55⁄8 5.6250 5.5438 5.4762 5.4897 0 25 23.4 23.8

53⁄4 . . . 5.7500 5.6688 5.6012 5.6147 0 24 24.5 24.9. . . 57⁄8 5.8750 5.7938 5.7262 5.7397 0 24 25.6 26.0

6 . . . 6.0000 5.9188 5.8512 5.8647 0 23 26.8 27.1

NOTES:(1) For information only.(2) See formulas in Nonmandatoray Appendix B, para. B-1.(3) Standard size of the UNC series.

78






9⁄16 [Note (3)] . . . 0.5625 0.5084 0.4633 0.4723 2 59 0.162 0.1825⁄8 . . . 0.6250 0.5709 0.5258 0.5348 2 40 0.210 0.232

. . . 11⁄16 0.6875 0.6334 0.5883 0.5973 2 24 0.264 0.289

3⁄4 . . . 0.7500 0.6959 0.6508 0.6598 2 11 0.323 0.351. . . 13⁄16 0.8125 0.7584 0.7133 0.7223 2 0 0.390 0.420

7⁄8 . . . 0.8750 0.8209 0.7758 0.7848 1 51 0.462 0.495. . . 15⁄16 0.9375 0.8834 0.8383 0.8473 1 43 0.540 0.576

1 [Note (3)] . . . 1.0000 0.9459 0.9008 0.9098 1 36 0.625 0.663. . . 11⁄16 1.0625 1.0084 0.9633 0.9723 1 30 0.715 0.756

11⁄8 [Note (3)] . . . 1.1250 1.0709 1.0258 1.0348 1 25 0.812 0.856. . . 13⁄16 1.1875 1.1334 1.0883 1.0973 1 20 0.915 0.961

11⁄4 [Note (3)] . . . 1.2500 1.1959 1.1508 1.1598 1 16 1.024 1.073. . . 15⁄16 1.3125 1.2584 1.2133 1.2223 1 12 1.139 1.191

13⁄8 [Note (3)] . . . 1.3750 1.3209 1.2758 1.2848 1 9 1.260 1.315. . . 17⁄16 1.4375 1.3834 1.3383 1.3473 1 6 1.388 1.445

11⁄2 [Note (3)] . . . 1.5000 1.4459 1.4008 1.4098 1 3 1.52 1.58. . . 19⁄16 1.5625 1.5084 1.4633 1.4723 1 0 1.66 1.72

15⁄8 . . . 1.6250 1.5709 1.5258 1.5348 0 58 1.81 1.87. . . 111⁄16 1.6875 1.6334 1.5883 1.5973 0 56 1.96 2.03

13⁄4 . . . 1.7500 1.6959 1.6508 1.6598 0 54 2.12 2.19. . . 113⁄16 1.8125 1.7584 1.7133 1.7223 0 52 2.28 2.35

17⁄8 . . . 1.8750 1.8209 1.7758 1.7848 0 50 2.45 2.53. . . 115⁄16 1.9375 1.8834 1.8383 1.8473 0 48 2.63 2.71

2 . . . 2.0000 1.9459 1.9008 1.9098 0 47 2.81 2.89. . . 21⁄8 2.1250 2.0709 2.0258 2.0348 0 44 3.19 3.28

21⁄4 . . . 2.2500 2.1959 2.1508 2.1598 0 42 3.60 3.69. . . 23⁄8 2.3750 2.3209 2.2758 2.2848 0 39 4.04 4.13

21⁄2 . . . 2.5000 2.4459 2.4008 2.4098 0 37 4.49 4.60. . . 25⁄8 2.6250 2.5709 2.5258 2.5348 0 35 4.97 5.08

23⁄4 . . . 2.7500 2.6959 2.6508 2.6598 0 34 5.48 5.59. . . 27⁄8 2.8750 2.8209 2.7758 2.7848 0 32 6.01 6.13

3 . . . 3.0000 2.9459 2.9008 2.9098 0 31 6.57 6.69. . . 31⁄8 3.1250 3.0709 3.0258 3.0348 0 30 7.15 7.28

31⁄4 . . . 3.2500 3.1959 3.1508 3.1598 0 29 7.75 7.89. . . 33⁄8 3.3750 3.3209 3.2758 3.2848 0 27 8.38 8.52

31⁄2 . . . 3.5000 3.4459 3.4008 3.4098 0 26 9.03 9.18. . . 35⁄8 3.6250 3.5709 3.5258 3.5348 0 26 9.71 9.86

33⁄4 . . . 3.7500 3.6959 3.6508 3.6598 0 25 10.42 10.57. . . 37⁄8 3.8750 3.8209 3.7758 3.7848 0 24 11.14 11.30

4 . . . 4.0000 3.9459 3.9008 3.9098 0 23 11.90 12.06. . . 41⁄8 4.1250 4.0709 4.0258 4.0348 0 22 12.67 12.84

41⁄4 . . . 4.2500 4.1959 4.1508 4.1598 0 22 13.47 13.65. . . 43⁄8 4.3750 4.3209 4.2758 4.2848 0 21 14.30 14.48

79








41⁄2 . . . 4.5000 4.4459 4.4008 4.4098 0 21 15.1 15.3. . . 45⁄8 4.6250 4.5709 4.5258 4.5348 0 20 16.0 16.2

43⁄4 . . . 4.7500 4.6959 4.6508 4.6598 0 19 16.9 17.1. . . 47⁄8 4.8750 4.8209 4.7758 4.7848 0 19 17.8 18.0

5 . . . 5.0000 4.9459 4.9008 4.9098 0 18 18.8 19.0. . . 51⁄8 5.1250 5.0709 5.0258 5.0348 0 18 19.8 20.0

51⁄4 . . . 5.2500 5.1959 5.1508 5.1598 0 18 20.8 21.0. . . 53⁄8 5.3750 5.3209 5.2758 5.2848 0 17 21.8 22.0

51⁄2 . . . 5.5000 5.4459 5.4008 5.4098 0 17 22.8 23.1. . . 55⁄8 5.6250 5.5709 5.5258 5.5348 0 16 23.9 24.1

53⁄4 . . . 5.7500 5.6959 5.6508 5.6598 0 16 25.0 25.2. . . 57⁄8 5.8750 5.8209 5.7758 5.7848 0 16 26.1 26.4

6 . . . 6.0000 5.9459 5.9008 5.9098 0 15 27.3 27.5

NOTES:(1) For information only.(2) See formulas in Nonmandatory Appendix B, para. B-1.(3) Standard sizes of the UNC or UNF series.

80






3⁄8 [Note (3)] . . . 0.3750 0.3344 0.3005 0.3073 3 24 00678 0.07757⁄16 . . . 0.4375 0.3969 0.3630 0.3698 2 52 0.0997 0.11141⁄2 . . . 0.5000 0.4594 0.4255 0.4323 2 29 0.1378 0.1519⁄16 . . . 0.5625 0.5219 0.4880 0.4948 2 11 0.182 0.1985⁄8 . . . 0.6250 0.5844 0.5505 0.5573 1 57 0.232 0.250

. . . 11⁄16 0.6875 0.6469 0.6130 0.6198 1 46 0.289 0.308

3⁄4 [Note (3)] . . . 0.7500 0.7094 0.6755 0.6823 1 36 0.351 0.373. . . 13⁄16 0.8125 0.7719 0.7380 0.7448 1 29 0.420 0.444

7⁄8 . . . 0.8750 0.8344 0.8005 0.8073 1 22 0.495 0.521. . . 15⁄16 0.9375 0.8969 0.8630 0.8698 1 16 0.576 0.604

1 . . . 1.0000 0.9594 0.9255 0.9323 1 11 0.663 0.693. . . 11⁄16 1.0625 1.0219 0.9880 0.9948 1 7 0.756 0.788

11⁄8 . . . 1.1250 1.0844 1.0505 1.0573 1 3 0.856 0.889. . . 13⁄16 1.1875 1.1469 1.1130 1.1198 1 0 0.961 0.997

11⁄4 . . . 1.2500 1.2094 1.1755 1.1823 0 57 1.073 1.111. . . 15⁄16 1.3125 1.2719 1.2380 1.2448 0 54 1.191 1.230

13⁄8 . . . 1.3750 1.3344 1.3005 1.3073 0 51 1.315 1.356. . . 17⁄16 1.4375 1.3969 1.3630 1.3698 0 49 1.445 1.488

11⁄2 . . . 1.5000 1.4594 1.4255 1.4323 0 47 1.58 1.63. . . 19⁄16 1.5625 1.5219 1.4880 1.4948 0 45 1.72 1.77

15⁄8 . . . 1.6250 1.5844 1.5505 1.5573 0 43 1.87 1.92. . . 111⁄16 1.6875 1.6469 1.6130 1.6198 0 42 2.03 2.08

13⁄4 . . . 1.7500 1.7094 1.6755 1.6823 0 40 2.19 2.24. . . 113⁄16 1.8125 1.7719 1.7380 1.7448 0 39 2.35 2.41

17⁄8 . . . 1.8750 1.8344 1.8005 1.8073 0 37 2.53 2.58. . . 115⁄16 1.9375 1.8969 1.8630 1.8698 0 36 2.71 2.77

2 . . . 2.0000 1.9594 1.9255 1.9323 0 35 2.89 2.95. . . 21⁄8 2.1250 2.0844 2.0505 2.0573 0 33 3.28 3.35

21⁄4 . . . 2.2500 2.2094 2.1755 2.1823 0 31 3.69 3.76. . . 23⁄8 2.3750 2.3344 2.3005 2.3073 0 29 4.13 4.21

21⁄2 . . . 2.5000 2.4594 2.4255 2.4323 0 28 4.60 4.67. . . 25⁄8 2.6250 2.5844 2.5505 2.5573 0 26 5.08 5.16

23⁄4 . . . 2.7500 2.7094 2.6755 2.6823 0 25 5.59 5.68. . . 27⁄8 2.8750 2.8344 2.8005 2.8073 0 24 6.13 6.22

3 . . . 3.0000 2.9594 2.9255 2.9323 0 23 6.69 6.78. . . 31⁄8 3.1250 3.0844 3.0505 3.0573 0 22 7.28 7.37

31⁄4 . . . 3.2500 3.2094 3.1755 3.1823 0 21 7.89 7.99. . . 33⁄8 3.3750 3.3344 3.3005 3.3073 0 21 8.52 8.63

31⁄2 . . . 3.5000 3.4594 3.4255 3.4323 0 20 9.18 9.29. . . 35⁄8 3.6250 3.5844 3.5505 3.5573 0 19 9.86 9.98

33⁄4 . . . 3.7500 3.7094 3.6755 3.6823 0 18 10.57 10.69. . . 37⁄8 3.8750 3.8344 3.8005 3.8073 0 18 11.30 11.43

81








4 . . . 4.0000 3.9594 3.9255 3.9323 0 17 12.06 12.19. . . 41⁄8 4.1250 4.0844 4.0505 4.0573 0 17 12.84 12.97

41⁄4 . . . 4.2500 4.2094 4.1755 4.1823 0 16 13.65 13.78. . . 43⁄8 4.3750 4.3344 4.3005 4.3073 0 16 14.48 14.62

41⁄2 . . . 4.5000 4.4594 4.4255 4.4323 0 15 15.34 15.5. . . 45⁄8 4.6250 4.5844 4.5505 4.5573 0 15 16.2 16.4

43⁄4 . . . 4.7500 4.7094 4.6755 4.6823 0 15 17.1 17.3. . . 47⁄8 4.8750 4.8344 4.8005 4.8073 0 14 18.0 18.2

5 . . . 5.0000 4.9594 4.9255 4.9323 0 14 19.0 19.2. . . 51⁄8 5.1250 5.0844 5.0505 5.0573 0 13 20.0 20.1

51⁄4 . . . 5.2500 5.2094 5.1755 5.1823 0 13 21.0 21.1. . . 53⁄8 5.3750 5.3344 5.3005 5.3073 0 13 22.0 22.2

51⁄2 . . . 5.5000 5.4594 5.4255 5.4323 0 13 23.1 23.2. . . 55⁄8 5.6250 5.5844 5.5505 5.5573 0 12 24.1 24.3

53⁄4 . . . 5.7500 5.7094 5.6755 5.6823 0 12 25.2 25.4. . . 57⁄8 5.8750 5.8344 5.8005 5.8073 0 12 26.4 26.5

6 . . . 6.0000 5.9594 5.9255 5.9323 0 11 27.5 27.7

NOTES:(1) For information only.(2) See formulas in Nonmandatory Appendix B, para. B-1.(3) Standard sizes of the UNC or UNF series.

82






1⁄4 [Note (3)] . . . 0.2500 0.2175 0.1905 0.1959 4 11 0.0269 0.03185⁄16 . . . 0.3125 0.2800 0.2530 0.2584 3 15 0.0481 0.05473⁄8 . . . 0.3750 0.3425 0.3155 0.3209 2 40 0.0755 0.08367⁄16 [Note (3)] . . . 0.4375 0.4050 0.3780 0.3834 2 15 0.1090 0.1187

1⁄2 [Note (3)] . . . 0.5000 0.4675 0.4405 0.4459 1 57 0.1486 0.1609⁄16 . . . 0.5625 0.5300 0.5030 0.5084 1 43 0.194 0.2075⁄8 . . . 0.6250 0.5925 0.5655 0.5709 1 32 0.246 0.261

. . . 11⁄16 0.6875 0.6550 0.6280 0.6334 1 24 0.304 0.320

3⁄4 [Note (3)] . . . 0.7500 0.7175 0.6905 0.6959 1 16 0.369 0.386. . . 13⁄16 0.8125 0.7800 0.7530 0.7584 1 10 0.439 0.458

[Note (3)]7⁄8 [Note (3)] . . . 0.8750 0.8425 0.8155 0.8209 1 5 0.515 0.536

. . . 15⁄16 0.9375 0.9050 0.8780 0.8834 1 0 0.598 0.620[Note (3)]

1 [Note (3)] . . . 1.0000 0.9675 0.9405 0.9459 0 57 0.687 0.711. . . 11⁄16 1.0625 1.0300 1.0030 1.0084 0 53 0.782 0.807

11⁄8 . . . 1.1250 1.0925 1.0655 1.0709 0 50 0.882 0.910. . . 13⁄16 1.1875 1.1550 1.1280 1.1334 0 47 0.990 1.018

11⁄4 . . . 1.2500 1.2175 1.1905 1.1959 0 45 1.103 1.133. . . 15⁄16 1.3125 1.2800 1.2530 1.2584 0 43 1.222 1.254

13⁄8 . . . 1.3750 1.3425 1.3155 1.3209 0 41 1.348 1.382. . . 7⁄16 1.4375 1.4050 1.3780 1.3834 0 39 1.479 1.51

11⁄2 . . . 1.5000 1.4675 1.4405 1.4459 0 37 1.62 1.65. . . 19⁄16 1.5625 1.5300 1.5030 1.5084 0 36 1.76 1.80

15⁄8 . . . 1.6250 1.5925 1.5655 1.5709 0 34 1.91 1.95. . . 111⁄16 1.6875 1.6550 1.6280 1.6334 0 33 2.07 2.11

13⁄4 . . . 1.7500 1.7175 1.6905 1.6959 0 32 2.23 2.27. . . 113⁄16 1.8125 1.7800 1.7530 1.7584 0 31 2.40 2.44

17⁄8 . . . 1.8750 1.8425 1.8155 1.8209 0 30 2.57 2.62. . . 115⁄16 1.9375 1.9050 1.8780 1.8834 0 29 2.75 2.80

2 . . . 2.0000 1.9675 1.9405 1.9459 0 28 2.94 2.99. . . 21⁄8 2.1250 2.0925 2.0655 2.0709 0 26 3.33 3.39

21⁄4 . . . 2.2500 2.2175 2.1905 2.1959 0 25 3.75 3.81. . . 23⁄8 2.3750 2.3425 2.3155 2.3209 0 23 4.19 4.25

21⁄2 . . . 2.5000 2.4675 2.4405 2.4459 0 22 4.66 4.72. . . 25⁄8 2.6250 2.5925 2.5655 2.5709 0 21 5.15 5.21

23⁄4 . . . 2.7500 2.7175 2.6905 2.6959. 0 20 5.66 5.73. . . 27⁄8 2.8750 2.8425 2.8155 2.8209 0 19 6.20 6.27

3 . . . 3.0000 2.9675 2.9405 2.9459 0 18 6.77 6.84

NOTES:(1) For information only.(2) See formulas in Nonmandatory Appendix B, para. B-1.(3) Standard sizes of the UNC, UNF, or UNEF series.

83





Lead AngleUNR Designat BasicMinor Basic Section at

PitchBasic Basic Diameter Minor Minor TensileDiameter,Major Pitch External, Diameter Diameter at Stress Area,

Nominal Size, in. �Diameter, Diameter, d3, in. Internal D − 2hb, sq in. sq in.Primary Secondary D, in. D2, in. (Ref.) D1, in. deg Min. [Note (1)] [Notes (1), (2)]

. . . 12 (0.216) 0.2160 0.1928 0.1734 0.1773 3 22 0.0226 0.0258[Note (3)]

1⁄4 [Note (3)] . . . 0.2500 0.2268 0.2074 0.2113 2 52 0.0326 0.03645⁄16 . . . 0.3125 0.2893 0.2699 0.2738 2 15 0.0556 0.06063⁄8 . . . 0.3750 0.3518 0.3324 0.3363 1 51 0.0848 0.09097⁄16 [Note (3)] . . . 0.4375 0.4143 0.3949 0.3988 1 34 0.1201 0.1274

1⁄2 [Note (3)] . . . 0.5000 0.4768 0.4574 0.4613 1 22 0.162 0.1709⁄16 . . . 0.5625 0.5393 0.5199 0.5238 1 12 0.209 0.2195⁄8 . . . 0.6250 0.6018 0.5824 0.5863 1 5 0.263 0.274

. . . 11⁄16 0.6875 0.6643 0.6449 0.6488 0 59 0.323 0.335

3⁄4 . . . 0.7500 0.7268 0.7074 0.7113 0 54 0.389 0.402. . . 13⁄16 0.8125 0.7893 0.7699 0.7738 0 50 0.461 0.475

7⁄8 . . . 0.8750 0.8518 0.8324 0.8363 O 46 0.539 0.554. . . 15⁄16 0.9375 0.9143 0.8949 0.8988 O 43 0.624 0.640

1 . , . 1.0000 0.9768 0.9574 0.9613 O 40 0.714 0.732. . . 11⁄16 1.0625 1.0393 1.0199 1.0238 O 38 0.811 0.830

11⁄8 . . . 1.1250 1.1018 1.0824 1.0863 O 35 0.914 0.933. . . 13⁄16 1.1875 1.1643 1.1449 1.1488 O 34 1.023 1.044

11⁄4 . . . 1.2500 1.2268 1.2074 1.2113 O 32 1.138 1.160. . . 15⁄16 1.3125 1.2893 1.2699 1.2738 O 30 1.259 1.282

13⁄8 . . . 1.3750 1.3518 1.3324 1.3363 O 29 1.386 1.411. . . 17⁄16 1.4375 1.4143 1.3949 1.3988 O 28 1.52 1.55

11⁄2 . . . 1.5000 1.4768 1.4574 1.4613 0 26 1.66 1.69

NOTES:(1) For information only.(2) See formulas in Nonmandatory Appendix B, para. B-1.(3) Standard sizes of the UNF or UNEF series.

84



Lead AngleUNR Designat BasicMinor Basic Section at

PitchBasic Basic Diameter Minor Minor TensileDiameter,Major Pitch External, Diameter Diameter at Stress Area,

Nominal Size, in. �Diameter, Diameter, d3, in. Internal, D − 2hb, sq in. sq in.Primary Secondary D, in. D2, in. (Ref.) D1, in. deg Min. [Note (1)] [Notes (1), (2)]

6 (0.138) [Note (3)] . . . 0.1380 0.1177 0.1008 0.1042 4 50 0.00745 0.009098 (0.164) [Note (3)] . . . 0.1640 0.1437 0.1268 0.1302 3 58 0.01196 0.0140

10 (0.190) [Note (3)] . . . 0.1900 0.1697 0.1528 0.1562 3 21 0.01750 0.0200. . . 12 (0.216) 0.2160 0.1957 0.1788 0.1822 2 55 0.0242 0.0270

[Note (3)]

1⁄4 [Note (3)] . . . 0.2500 0.2297 0.2128 0.2162 2 29 0.0344 0.03795⁄16 [Note (3)] . . . 0.3125 0.2922 0.2753 0.2787 1 57 0.0581 0.06253⁄8 [Note (3)] . . . 0.3750 0.3547 0.3378 0.3412 1 36 0.0878 0.09327⁄16 . . . 0.4375 0.4172 0.4003 0.4037 1 22 0.1237 0.1301

1⁄2 . . . 0.5000 0.4797 0.4628 0.4662 1 11 0.166 0.1739⁄16 . . . 0.5625 0.5422 0.5253 0.5287 1 3 0.214 0.2225⁄8 . . . 0.6250 0.6047 0.5878 0.5912 0 57 0.268 0.278

. . . 11⁄16 0.6875 0.6672 0.6503 0.6537 0 51 0.329 0.339

3⁄4 . . . 0.7500 0.7297 0.7128 0.7162 0 47 0.395 0.407. . . 13⁄16 0.8125 0.7922 0.7753 0.7787 0 43 0.468 0.480

7⁄8 . . . 0.8750 0.8547 0.8378 0.8412 0 40 0.547 0.560. . . 15⁄16 0.9375 0.9172 0.9003 0.9037 0 37 0.632 0.646

1 . . . 1.0000 0.9797 0.9628 0.9662 0 35 0.723 0.738

NOTES:(1) For information only.(2) See formulas in Nonmandatory Appendix B, para. B-1.(3) Standard sizes of the UNC, UNF, or UNEF series.

85




Table 17A Outline Guide for Determining Limits of Size of External Threads

Major Diameter, d Pitch Diameter, d2ThreadClass Max. Min. Max. Min. Minor Diameter, d1

1A Nominal size Maximum, Maximum major Maximum, See paras. 8.3.1(e) and (f).minus allowance minus tolerance diameter minus hb minus tolerance Established by crest of

(Table 5, col. 13) new tool and minimumminor diameter of GOthread gage.

2A Nominal size Maximum, Maximum major Maximum, See paras. 8.3.1(e) and (f).minus allowance minus tolerance diameter minus hb minus tolerance Established by crest of


3A Nominal size Maximum, Maximum major Maximum, See paras. 8.3.1(e) and (f).minus tolerance diameter minus hb minus tolerance Established by crest of


Table 17B Outline Guide for Determining Limits of Size of Internal Threads

Minor Diameter, D1 Pitch Diameter, D2ThreadClass Min. Max. Min. Max. Major Diameter, D

1B Nominal size minus 2hn Minimum, plus Nominal size minus hb Minimum, See paras. 8.3.2(a) and (b).(Table 5, col. 15) tolerance (Table 5, col. 13) plus tolerance Established by crest of

new tool and maximummajor diameter of GOthread gage.





86


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obta

inth

efin

alva

lue

ofd 2

min

.d 2

min

.p0.

4720

...

88


Tabl

e18

AEx

ampl

esof

Exte

rnal

Inch

Scre

wTh

read

s,(C

ont’

d)

Thre

adS

izep

1 ⁄ 2–

28or

0.50

00–

28U

NEF

-2A

Char

acte

rist

icD

escr

ipti

onEx

ampl

eof

Siz

eCa

lcul

atio

nA

ddit

iona

lIn

form

atio

n

(5)

Max

imum

exte

rnal

UN

Rm

inor

diam

eter

(d3

max

.)d 3

max

.pd

max

.−2h

s..

.p

Max

imum

exte

rnal

maj

ordi

amet

er(d

max

.)–

doub

lehe

ight

2hsp

1.19

0784

93P

...

ofex

tern

alU

NR

thre

ad(2

h s)

2hsp

1.19

0784

93(0

.035

7142

9)A

llth

read

calc

ulat

ions

are

tobe

perf

orm

edus

ing

(P)

roun

ded

toei

ght

deci

mal

plac

es.

2hsp

0.04

2528

...

d 3m

ax.p

0.49

89−

0.04

2528

...

d 3m

ax.p

0.45

6372

This

figur

eis

roun

ded

tofo

urde

cim

alpl

aces

toob

tain

the

final

valu

eof

d 3m

ax.

d 3m

ax.p

0.45

64..

.

(6)

Max

imum

exte

rnal

UN

min

ordi

amet

er(d

1m

ax.)

d 1m

ax.p

dm

ax.−

2hs

...

pM

axim

umex

tern

alm

ajor

diam

eter

(dm

ax.)

–do

uble

heig

ht2h

sp

1.08

2531

75P

For

UN

thre

ads,

2hsp

2hn

ofex

tern

alU

Nth

read

(2h s

)2h

sp

1.08

2531

75(0

.035

7142

9)A

llth

read

calc

ulat

ions

are

tobe

perf

orm

edus

ing

(P)

roun

ded

toei

ght

deci

mal

plac

es.

2hsp

0.03

8662

...

d 1m

ax.p

0.49

89−

0.03

8662

...

d 1m

ax.p

0.46

0238

This

figur

eis

roun

ded

tofo

urde

cim

alpl

aces

toob

tain

the

final

valu

eof

d 1m

ax.

d 1m

ax.p

0.46

02..

.

GEN

ERA

LN

OTE

S:(a

)A

lldi

men

sion

sex

pres

sed

inin

ches

for

calc

ulat

ions

inth

ista

ble.

(b)

Pp

1/n

p1/

28p

0.03

5714

29.

89




Tabl

e18

BEx

ampl

esof

Inte

rnal

Scre

wTh

read

s

Thre

adS

izep

1 ⁄ 2–

28or

0.50

00–

28U

NEF

-2B

Char

acte

rist

icD

escr

ipti

onEx

ampl

eof

Siz

eCa

lcul

atio

nA

ddit

iona

lIn

form

atio

n

(1)

Min

imum

inte

rnal

min

ordi

amet

er(D

1m

in.)

D1

min

.pD

bsc

−2h

n..

.p

Bas

icm

ajor

diam

eter

(Dbs

c)−

doub

lehe

ight

ofin

tern

al2h

np

1.08

2531

75P

...

thre

ad(2

h n)

2hnp

1.08

2531

75(0

.035

7142

9)A

llth

read

calc

ulat

ions

are

tobe

perf

orm

edus

ing

(P)

roun

ded

toei

ght

deci

mal

plac

es.

2hnp

0.03

8662

...

D1

min

.p0.

5000

−0.

0386

62..

.D

1m

in.p

0.46

1338

For

the

Clas

s2B

thre

adus

edin

this

exam

ple,

this

figur

eis

roun

ded

toth

ree

deci

mal

plac

esto

obta

inth

efin

alva

lue

ofD

1m

in.

Oth

ersi

zes

and

clas

ses

are

expr

esse

din

afo

urpl

ace

deci

mal

.Se

epa

ra.

8.3.

2(e)

.D

1m

in.p

0.46

1..

.

(2)

Max

imum

inte

rnal

min

ordi

amet

er(D

1m

ax.)

D1

max

.pD

1m

in.(

tosi

xde

cim

alpl

aces

)+

TD1

See

para

.5.

8.2(

c)fo

rlim

itatio

nson

use

ofp

Min

imum

inte

rnal

min

ordi

amet

er(D

1m

in.)

roun

ded

tosi

xTD

1p

0.25

P−

0.4P

2th

isfo

rmul

a.de

cim

alpl

aces

+in

tern

alm

inor

diam

eter

tole

ranc

e(T

D1)

TD1

p0.

25(0

.035

7142

9)−

0.4

(0.0

3571

429)

2A

llth

read

calc

ulat

ions

are

tobe

perf

orm

edus

ing

(P)

roun

ded

toei

ght

deci

mal

plac

es.

TD1

p0.

25(0

.035

7142

9)−

0.4

(0.0

0127

6)..

.TD

1p

0.00

8929

−0.

0005

10..

.TD

1p

0.00

8419

...

TD1

p0.

0084

This

figur

eis

roun

ded

tofo

urde

cim

alpl

aces

toob

tain

the

final

valu

eof

TD1.

D1

max

.p0.

4613

38+

0.00

84..

.D

1m

ax.p

0.46

9757

For

the

Clas

s2B

thre

adus

edin

this

exam

ple,

this

figur

eis

roun

ded

toth

ree

deci

mal

plac

esto

obta

inth

efin

alva

lue

ofD

1m

ax.

Oth

ersi

zes

and

clas

ses

are

expr

esse

din

afo

urpl

ace

deci

mal

.Se

epa

ra.

8.3.

2(e)

.D

1m

ax.p

0.47

0..

.

90


Tabl

e18

BEx

ampl

esof

Inte

rnal

Scr

ewTh

read

s(C

ont’

d)

Thre

adS

izep

1⁄ 2

–2

8or

0.5

00

0–

28

UN

EF-2

B

Ch

arac

teri

stic

Des

crip

tion

Exam

ple

ofS

ize

Calc

ulat

ion

Ad

dit

iona

lIn

form

atio

n

(3)

Min

imu

min

tern

alp

itch

dia

met

er(D

2m

in.)

D2

min

.p

Db

sc−

hb

..

.p

Bas

icm

ajor

dia

met

er(D

bsc

)−

twic

eth

eex

tern

alth

read

hb

p0

.64

95

19

05

P.

..

add

end

um

(hb)

hb

p0

.64

95

19

05

(0.0

35

71

42

9)

All

thre

adca

lcu

lati

ons

are

tob

ep

erfo

rmed

usi

ng

(P)

roun

ded

toei

ght

dec

imal

pla

ces.

hb

p0

.02

31

97

..

.D

2m

in.p

0.5

00

0−

0.0

23

19

7.

..

D2

min

.p

0.4

76

80

3Th

isfi

gure

isro

und

edto

fou

rd

ecim

alp

lace

sto

obta

inth

efi

nal

valu

eof

D2

min

.D

2m

in.p

0.4

76

8.

..

(4)

Max

imu

min

tern

alp

itch

dia

met

er(D

2m

ax.)

D2

max

.p

D2

min

.+

TD2

..

.p

Min

imu

min

tern

alp

itch

dia

met

er(D

2m

in.)

+in

tern

alp

itch

TD2

p1

.30

0(T

d2

for

Clas

s2

A)

The

cons

tan

t1

.30

0is

for

this

Clas

s2

Bex

am-

dia

met

erto

lera

nce

(TD

2)

ple

and

will

be

dif

fere

nt

for

Clas

ses

1B

and

3B

.S

eep

ara.

5.8

.2.

TD2

p1

.30

0(0

.00

36

68

)Fo

rth

eTd

2Cl

ass

2A

pit

chd

iam

eter

tole

ran

ce,

see

Tab

le1

8A

,(4

).Th

esi

xp

lace

dec

imal

pla

ceva

lue

isu

sed

.TD

2p

0.0

04

76

8.

..

TD2

p0

.00

48

This

figu

reis

roun

ded

tofo

ur

dec

imal

pla

ces

toob

tain

the

fina

lva

lue

ofTD

2.

D2

max

.p

0.4

76

8+

0.0

04

8.

..

D2

max

.p

0.4

81

6.

..

(5)

Min

imu

min

tern

alm

ajor

dia

met

er(D

min

.)D

min

.p

Db

sc.

..

pB

asic

maj

ord

iam

eter

(Db

sc)

Db

scp

0.5

00

0.

..

Dm

in.p

0.5

00

0.

..

GEN

ERA

LN

OTE

S:

(a)

All

dim

ensi

ons

exp

ress

edin

inch

esfo

rca

lcu

lati

ons

inth

ista

ble

.(b

)P

p1

/np

1/2

8p

0.0

35

71

42

9.

91




Table 19 Allowable Variation in 30 deg Basic HalfAngle of External and Internal Screw Threads

Allowable Variationin Half Angle

of Thread

Threads/in. ±deg Min.

80 3 0072 2 4564 2 3056 2 15

48 2 0044 1 5040 1 4536 1 35

32 1 3028 1 2027 1 2024 1 15

20 1 1018 1 0516 1 0014 0 55

13 0 5512 0 50111⁄2 0 5011 0 50

10 0 509 0 508 0 457 0 45

6 0 405 0 4041⁄2 0 404 0 40

GENERAL NOTE: See paras. 9.1.3 through 9.1.6 for applicability.

92


Table 20 General Symbols (See Fig. 6)

Symbol Dimension Remarks

d Major diameter, external threadD Major diameter, internal threadD3 Major diameter, rounded root,

internal threadd2 Pitch diameter, external threadD2 Pitch diameter, internal thread

d1 Minor diameter, external threadd3 Minor diameter, rounded root,

external threadD1 Minor diameter, internal threadP Pitchn p 1⁄ P Number of threads per unit

of length (per inch)

N p 1⁄ L Number of turns per unitof length (per inch)

H Height of fundamental triangleh Thread height (or depth)ha Addendumhd Dedendum

he Depth of thread engagement

hs Height of UN or UNR externalthread

hn Height of UN internal thread

has Addendum of external thread

Hb Twice the external threadaddendum

� Half angle of symmetrical thread

�1 Angle between leading flankof thread and normalto axis of thread

�2 Angle between followingflank of thread and normalto axis of thread

� Lead angle tan � pL

�(d2 or D2)Radius of rounding at:

rcs crest of external threadrrs root of external threadRcn crest of internal threadRrn root of internal thread

Radial distance from apex offundamental triangle to:

scs rounded crest of external threadsrs rounded root of external threadscn rounded crest of internal threadsrn rounded root of internal thread

Distance from apex offundamental triangle to:

fcs flat at crest of external thread

93

Table 20 General Symbols (See Fig. 6) (Cont’d)

Symbol Dimension Remarks

frs flat at root of external threadfcn flat at crest of internal threadfrn flat at root of internal thread

Width of:F flat (general)Fcs flat at crest of external threadFrs flat at root of external threadFcn flat at crest of internal threadFrn flat at root of internal thread

es Allowance at major, pitch, and minordiameters of external thread

EI Allowance at major, pitch, and minordiameters of internal thread

Lts Length of complete external thread

Ltn Length of complete internal thread,including chamfer

LE Length of thread engagement

W Diameter of measuring wires

Mw Measurement over wires

C Correction to measurement over d2 or D2 pbest size wires to give pitch Mw − C − cdiameter C p W (1 + cosec �)

−(cot �)/2n�′ Wire anglec Wire angle correction for See FED-STD-H28/6

large lead angles

Prefix Examples: Variation inSymbol pitch �Piwith � Variation in any dimension variation in half

angle, � �1 or ��2

�d2�, Pitch diameter�D2� equivalent of variation

in flank angles

�d2�, Pitch diameter�D2� equivalent of variation

in pitch (lead)

GENERAL NOTE: Refer to ASME B1.7 for latest symbol identification.Greek alphabet is below.

�, � p Alpha�, � p Beta� , p Gamma�, p Delta�, � p Epsilon , � p Zeta�, � p Eta�, � p Theta�, � p Iota�, � p Kappa�, � p Lambda�, � p Mu

�, � p Nu�, � p Xi�, � p Omicron , � p Pi!, " p Rho#, $ p Sigma%, & p Tau', ( p Upsilon), * p Phi+, , p Chi-, . p Psi/, 0 p Omega



ASME B1.1-2003

NONMANDATORY APPENDIX ATERMINOLOGY AND IDENTIFICATION OF UNIFIED INCH SCREW

THREADS

A-1 TERMINOLOGY

All terms relating to screw threads used in this Stan-dard are defined in ASME B1.7.

0.625H

0.75H

0.25P

UN External Thread

0.125P

0.25P

0.25P

0.125P 0.3125P

0.5625H

0.75H

0.6667H

0.125P0.125P 0.3125P

0.125P

Nominalminor diam.

Will assemble withUN or UNJ internal

0.125P

P (pitch)

rad. = 0.14434PH(fundamental

triangle)

rad. = 0.10826Prad. = 0.18042P

rad. = 0.15011P

Nominalminor diam.

Will assemble withUN or UNJ internal

Minimumminor diam.

Maximumminor diam.

Assembles onlywith UNJ internal

Root to clear 0.125P width, may be flat or rounded

UNR External Thread

UNJ Internal ThreadUN Internal Thread

UNJ External Thread

Will notassemblewith UNJexternalthread

Root to clear 0.125P width, flat or roundedAssembles

with allUN

externalthread

Fig. A-1 Identification of 60-deg Inch Screw Threads Within the Scope of ASME B1 Committee

95

A-2 IDENTIFICATIONThe various unified screw threads covered in B1 stan-

dards are compared in Fig. A-1 and Table A-1.



ASME B1.1-2003 NONMANDATORY APPENDIX A

Table A-1 Identification of 60-deg lnch Screw Threads Within the Scope of ASMEB1 Committee

UN Threads, UNR Threads, UNJ Threads, Internal andThread Identification Internal and External External Only External

ASME standards documents B1.1, Unified Inch Screw B1.1, Unified Inch Screw B1.15, Unified Inch ScrewThreads; B1.2, Gages and Gag- Threads; B1.2, Gages and Gag- Threads — UNJ Threading for Unified Inch Screw ing for Unified Inch Screw Form; draft of B1.2,Threads Threads Gages and Gaging for

Unified Inch ScrewThreads

External root External thread root may be flat Rounded root specified Rounded root specifiedor rounded

External minor diameter External thread minor diameter is External thread minor diameter is External thread minornot toleranced not toleranced diameter is toleranced

External threads UN Classes 1A, 2A, and 3A UNR Classes 1A, 2A, and 3A UNJ Classes 2A and 3Amate only with UNJinternal threads

Internal threads UN Classes 1B, 2B, and 3B No internal threads designated UNJ Classes 2B and 3BUNR; UNR mates with UN (no rounding requiredinternal threads on internal thread root)

GENERAL NOTES:(a) The above cannot be used as a working sheet. Refer to the appropriate standards, as listed, for complete thread

details and conformance data.(b) The appropriate current standard is the authoritative document for complete details and data and takes precedence

over this sheet.(c) These standards may be purchased from the ASME Order Department, 22 Law Drive, Box 2300, Fairfield, NJ 07007-

2300: telephone (201) 882-1167 or 1-800-THE-ASME.

96

ASME B1.1-2003

NONMANDATORY APPENDIX BTHREAD STRENGTH DESIGN FORMULAS

B-1 THREAD TENSILE STRESS AREA

The following thread tensile stress area formulas areused for the purpose of product acceptance computa-tions. Tensile stress area:

As p 3.1416 �D2

2−

3H16 �

2

or

As p 0.7854 �D −0.9743

1/P �2

where

D p basic major diameterD2 p basic pitch diameter

1/P p number of threads per inch

For 3H/16, see Table 5.

B-2 THREAD SHEAR DATA

The following formulas for thread shear areas are geo-metric minimum values. Shear (thread stripping)strengths of screw threads under load are dependent,in addition, on mating component relative materialstrengths, nut geometry, and coefficient of frictionbetween thread bearing surfaces. Effective shear areasare therefore somewhat less than the geometric values.Thread geometric shear areas:

ASn p 3.1416 (1/P)(LE)(d min.)

� � 12(1/P)

+ 0.57735 (d min. − D2 max.)�ASs p 3.1416 (1/P)(LE)(D1 max.)

� � 12(1/P)

+ 0.57735 (d2 min. − D1 max.)�

97

where

ASn p minimum thread shear area for internalthreads

ASs p minimum thread shear area for externalthreads

1/P p number of threads per inchLE p length of engagement

d min. p minimum major diameter of externalthread

d2 min. p minimum pitch diamter of external threadD1 max. p maximum minor diameter of internal

threadD2 max. p maximum pitch diameter of internal

thread

B-3 LENGTH OF THREAD ENGAGEMENT

In general, the length of engagement of mating threadsis selected to utilize full tensile strength of a bolt prior toshearing of nut threads. Other applications may requireinternal thread shear prior to failure of the externallythreaded part. For noncritical design, the following for-mulas are often used for approximation:

tensile strength of externally threaded part p StAs

shear strength of threads p 0.5St (ASn or ASs)

whereSt p ultimate tensile strength of material, psi

An internationally accepted study on the subject waspublished in the 1977 Transactions of the Society ofAutomotive Engineers as paper number 770420, Analysisand Design of Threaded Assemblies, by E. M. Alexander.



ASME B1.1-2003

NONMANDATORY APPENDIX CUNIFIED INCH SCREW THREADS — METRIC TRANSLATION

C-1 BACKGROUND

This Appendix presents a translation of unified inchscrew threads into metric units of measurement. It isvery important to recognize that this translation is notISO metric screw threads. The tables of limiting dimen-sions of standard and UNS/UNRS series threads andthe table of thread form data translated from inches tomillimeters presented in this Appendix implement thedecision of the B1 Committee that there should be officialmetric translations of inch screw thread standards tobetter fill communication needs in internationalexchange of technical data. This philosophy originatedat the May 4, 1964, meeting of the Committee and wasapproved by a letter ballot of the Committee on Novem-ber 2, 1966.

The tables in this Appendix were originally publishedas USAS B1.1a-1968 Supplement to USAS B1.1-1960, inthe interest of meeting urgent needs of industry.

C-2 DIMENSIONS

All dimensions in this Appendix are given in millime-ters unless otherwise specified. Metric values in the lim-iting dimension tables are translations of the inch valuestabulated in ASME B1.1.

The values in Table C-1 are a direct soft conversionof Table 2 in this Standard. All inch values weremultiplied by 25.4 and rounded to four decimal places,per the rounding policy stated in ASME B1.30. Similarly,Tables C-2 and C-3 are soft conversions of Tables D-1and 5, respectively.

Where it is necessary to use metric values of threadsfor which the metric limiting dimensions are not tabu-lated herein, the inch values should be determined inaccordance with para. 8 of ASME B1.1 before translating

98

to metric values and rounding by the method prescribedin the foregoing paragraph.

C-3 DESIGNATIONS

Designation of unified inch screw threads expressedin metric dimensions shall be as prescribed in paras.C-3.1 and C-3.2.

C-3.1 Metric Drawings or Documents

On metric drawings or documents, the designationshall specify, in sequence, the nominal size (expressed indecimal inches), the number of threads per inch, threadseries symbol, and thread class symbol. All supplemen-tal dimensions shall be as shown in metric units. Theequivalent inch dimensions, as indicated and enclosedin parentheses, may be included if desired.EXAMPLE (on metric drawing or metric document):0.250 – 28 UNF-2A (22)PD 5.7353 – 5.6515(0.2258 – 0.2225 in.) (optional)

C-3.2 Inch Drawings or Documents

On inch drawings or documents, the designation andsupplemental dimensions expressed in inches may befurther supplemented by inclusion of the equivalentmetric dimensions, so indicated and enclosed in paren-theses.EXAMPLE:0.250 – 28 UNF-2A (22)PD 0.2258 – 0.2225(5.7353 – 5.6515 mm) (optional)

C-4 TABLES

Tables C-1, C-2, and C-3 give limits of size for standardseries and UNS/UNRS series threads and thread formdata.

99

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UNR

Pitc

hDi

amet

eran

dPi

tch

Diam

eter

and

Min

orFu

nctio

nalD

iam

eter

[Not

esFu

nctio

nalD

iam

eter

Diam

eter

,M

ajor

Diam

eter

(4),

(5)]

[Not

es(4

),(5

)]No

min

alSi

zeSe

ries

Max

.M

ajor

Met

ricEq

uiva

lent

sM

inor

Diam

eter

and

Desi

g-Al

low

-M

ax.

Min

.M

ax.

Tole

r-[N

ote

(6)]

Tole

r-Di

amet

er,

Thre

ads/

in.

natio

nDi

a.Pi

tch

Clas

san

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

ance

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

Min

.

0–80

or0.

060–

80U

NF

1.52

400.

3175

2A0.

0127

1.51

131.

4300

...

1.30

561.

2598

0.04

571.

1328

2B1.

1811

1.30

561.

3183

1.37

670.

0584

1.52

403A

0.00

001.

5240

1.44

27..

.1.

3183

1.28

520.

0330

1.14

553B

1.18

111.

3056

1.31

831.

3614

0.04

321.

5240

1–64

or0.

073–

64U

NC

1.85

420.

3969

2A0.

0152

1.83

901.

7424

...

1.58

241.

5316

0.05

081.

3665

2B1.

4249

1.57

991.

5977

1.66

370.

0660

1.85

423A

0.00

001.

8542

1.75

77..

.1.

5977

1.55

960.

0381

1.38

183B

1.42

491.

5799

1.59

771.

6459

0.04

831.

8542

1–72

or0.

073–

72U

NF

1.85

420.

3528

2A0.

0152

1.83

901.

7501

...

1.61

041.

5621

0.04

831.

4199

2B1.

4732

1.61

041.

6256

1.68

910.

0635

1.85

423A

0.00

001.

8542

1.76

53..

.1.

6256

1.59

000.

0356

1.43

513B

1.47

321.

6104

1.62

561.

6739

0.04

831.

8542

2–56

or0.

086–

56U

NC

2.18

440.

4536

2A0.

0152

2.16

922.

0650

...

1.87

451.

8212

0.05

331.

6281

2B1.

6942

1.87

201.

8898

1.96

090.

0711

2.18

443A

0.00

002.

1844

2.08

03..

.1.

8898

1.84

910.

0406

1.64

343B

1.69

421.

8720

1.88

981.

9431

0.05

332.

1844

2–64

or0.

086–

64U

NF

2.18

440.

3969

2A0.

0152

2.16

922.

0726

...

1.91

261.

8618

0.05

081.

6967

2B1.

7551

1.91

011.

9279

1.99

640.

0686

2.18

443A

0.00

002.

1844

2.08

79..

.1.

9279

1.88

980.

0381

1.71

203B

1.75

511.

9101

1.92

791.

9787

0.05

082.

1844

3–48

or0.

099–

48U

NC

2.51

460.

5292

2A0.

0178

2.49

682.

3825

...

2.15

392.

0955

0.05

841.

8669

2B1.

9406

2.14

632.

1717

2.24

790.

0762

2.51

463A

0.00

002.

5146

2.40

03..

.2.

1717

2.12

850.

0432

1.88

473B

1.94

062.

1463

2.17

172.

2276

0.05

592.

5146

3–56

or0.

099–

56U

NF

2.51

460.

4536

2A0.

0178

2.49

682.

3927

...

2.20

222.

1463

0.05

591.

9558

2B2.

0244

2.19

712.

2200

2.29

110.

0711

2.51

463A

0.00

002.

5146

2.41

05..

.2.

2200

2.17

930.

0406

1.97

363B

2.02

442.

1971

2.22

002.

2733

0.05

332.

5146

4–40

or0.

112–

40U

NC

2.84

480.

6350

2A0.

0203

2.82

452.

6949

...

2.41

302.

3495

0.06

352.

0676

2B2.

1565

2.38

512.

4333

2.51

710.

0838

2.84

483A

0.00

002.

8448

2.71

53..

.2.

4333

2.38

510.

0483

2.08

793B

2.15

652.

3851

2.43

332.

4943

0.06

102.

8448

4–48

or0.

112–

48U

NF

2.84

480.

5292

2A0.

0178

2.82

702.

7127

...

2.48

412.

4232

0.06

102.

1971

2B2.

2708

2.45

872.

5019

2.58

060.

0787

2.84

483A

0.00

002.

8448

2.73

05..

.2.

5019

2.45

620.

0457

2.21

493B

2.27

082.

4587

2.50

192.

5603

0.05

842.

8448

5–40

or0.

125–

40U

NC

3.17

500.

6350

2A0.

0203

3.15

473.

0251

...

2.74

322.

6772

0.06

602.

3978

2B2.

4867

2.69

752.

7635

2.84

730.

0838

3.17

503A

0.00

003.

1750

3.04

55..

.2.

7635

2.71

530.

0483

2.41

813B

2.48

672.

6975

2.76

352.

8270

0.06

353.

1750

5–44

or0.

125–

44U

NF

3.17

500.

5773

2A0.

0178

3.15

723.

0353

...

2.78

132.

7178

0.06

352.

4689

2B2.

5502

2.74

072.

7991

2.88

040.

0813

3.17

503A

0.00

003.

1750

3.05

31..

.2.

7991

2.75

080.

0483

2.48

673B

2.55

022.

7407

2.79

912.

8600

0.06

103.

1750

6–32

or0.

138–

32U

NC

3.50

520.

7938

2A0.

0203

3.48

493.

3325

...

2.96

932.

8981

0.07

112.

5400

2B2.

6416

2.89

562.

9896

3.08

360.

0940

3.50

523A

0.00

003.

5052

3.35

28..

.2.

9896

2.93

620.

0533

2.56

033B

2.64

162.

8931

2.98

963.

0582

0.06

863.

5052

6–40

or0.

138–

40U

NF

3.50

520.

6350

2A0.

0203

3.48

493.

3553

...

3.07

343.

0074

0.06

602.

7280

2B2.

8194

3.02

263.

0937

3.18

010.

0864

3.50

523A

0.00

003.

5052

3.37

57..

.3.

0937

3.04

290.

0508

2.74

833B

2.81

943.

0124

3.09

373.

1572

0.06

353.

5052

8–32

or0.

164–

32U

NC

4.16

560.

7938

2A0.

0229

4.14

273.

9903

...

3.62

713.

5535

0.07

373.

1979

2B3.

3020

3.53

063.

6500

3.74

650.

0965

4.16

563A

0.00

004.

1656

4.01

32..

.3.

6500

3.59

410.

0559

3.22

073B

3.30

203.

5255

3.65

003.

7211

0.07

114.

1656

NONMANDATORY APPENDIX C ASME B1.1-2003



100

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

(Con

t’d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UNR

Pitc

hDi

amet

eran

dPi

tch

Diam

eter

and

Min

orFu

nctio

nalD

iam

eter

[Not

esFu

nctio

nalD

iam

eter

Diam

eter

,M

ajor

Diam

eter

(4),

(5)]

[Not

es(4

),(5

)]No

min

alSi

zeSe

ries

Max

.M

ajor

Met

ricEq

uiva

lent

sM

inor

Diam

eter

and

Desi

g-Al

low

-M

ax.

Min

.M

ax.

Tole

r-[N

ote

(6)]

Tole

r-Di

amet

er,

Thre

ads/

in.

natio

nDi

a.Pi

tch

Clas

san

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

ance

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

Min

.

8–36

or0.

164–

36U

NF

4.16

560.

7056

2A0.

0203

4.14

534.

0056

...

3.68

813.

6170

0.07

113.

3045

2B3.

4036

3.60

683.

7084

3.79

980.

0914

4.16

563A

0.00

004.

1656

4.02

59..

.3.

7084

3.65

510.

0533

3.32

493B

3.40

363.

5966

3.70

843.

7770

0.06

864.

1656

10–

24or

0.19

0–24

UN

C4.

8260

1.05

832A

0.02

544.

8006

4.61

77..

.4.

1123

4.02

840.

0838

3.54

082B

3.68

303.

9370

4.13

774.

2469

0.10

924.

8260

3A0.

0000

4.82

604.

6431

...

4.13

774.

0742

0.06

353.

5662

3B3.

6830

3.94

974.

1377

4.21

890.

0813

4.82

60

10–

32or

0.19

0–32

UN

F4.

8260

0.79

382A

0.02

294.

8031

4.65

07..

.4.

2875

4.21

130.

0762

3.85

832B

3.96

244.

1656

4.31

044.

4094

0.09

914.

8260

3A0.

0000

4.82

604.

6736

...

4.31

044.

2520

0.05

843.

8811

3B3.

9624

4.16

814.

3104

4.38

400.

0737

4.82

60

12–

24or

0.21

6–24

UN

C5.

4864

1.05

832A

0.02

545.

4610

5.27

81..

.4.

7727

4.68

630.

0864

4.20

122B

4.34

344.

5974

4.79

814.

9098

0.11

185.

4864

3A0.

0000

5.48

645.

3035

...

4.79

814.

7320

0.06

604.

2266

3B4.

3434

4.58

984.

7981

4.88

190.

0838

5.48

64

12–

28or

0.21

6–28

UN

F5.

4864

0.90

712A

0.02

545.

4610

5.29

59..

.4.

8717

4.79

040.

0813

4.38

152B

4.49

584.

7244

4.89

715.

0038

0.10

675.

4864

3A0.

0000

5.48

645.

3213

...

4.89

714.

8362

0.06

104.

4069

3B4.

4958

4.71

684.

8971

4.97

590.

0787

5.48

64

12–

32or

0.21

6–32

UN

EF5.

4864

0.79

382A

0.02

545.

4610

5.30

86..

.4.

9454

4.86

410.

0813

4.51

612B

4.62

284.

8260

4.97

085.

0749

0.10

415.

4864

3A0.

0000

5.48

645.

3340

...

4.97

084.

9098

0.06

104.

5415

3B4.

6228

4.81

334.

9708

5.04

950.

0787

5.48

64

1 ⁄ 4–

20or

0.25

00–

20U

NC

6.35

001.

2700

1A0.

0279

6.32

216.

0122

...

5.49

665.

3543

0.14

224.

8108

1B4.

9784

5.25

785.

5245

5.70

990.

1854

6.35

002A

0.02

796.

3221

6.11

636.

0122

5.49

665.

4026

0.09

404.

8108

2B4.

9784

5.25

785.

5245

5.64

900.

1245

6.35

003A

0.00

006.

3500

6.14

43..

.5.

5245

5.45

340.

0711

4.83

873B

4.97

845.

2502

5.52

455.

6159

0.09

146.

3500

1 ⁄ 4–

28or

0.25

00–

28U

NF

6.35

000.

9071

1A0.

0254

6.32

466.

0757

...

5.73

535.

6083

0.12

705.

2451

1B5.

3594

5.58

805.

7607

5.92

580.

1651

6.35

002A

0.02

546.

3246

6.15

95..

.5.

7353

5.65

150.

0838

5.24

512B

5.35

945.

5880

5.76

075.

8699

0.10

926.

3500

3A0.

0000

6.35

006.

1849

...

5.76

075.

6972

0.06

355.

2705

3B5.

3594

5.56

265.

7607

5.84

200.

0813

6.35

00

1 ⁄ 4–

32or

0.25

00–

32U

NEF

6.35

000.

7938

2A0.

0254

6.32

466.

1722

...

5.80

905.

7277

0.08

135.

3797

2B5.

4864

5.68

965.

8344

5.94

110.

1067

6.35

003A

0.00

006.

3500

6.19

76..

.5.

8344

5.77

340.

0610

5.40

513B

5.48

645.

6617

5.83

445.

9131

0.07

876.

3500

5 ⁄ 16–

18or

0.31

25–

18U

NC

7.93

751.

4111

1A0.

0305

7.90

707.

5743

...

6.99

016.

8351

0.15

496.

2255

1B6.

4008

6.73

107.

0206

7.22

120.

2007

7.93

752A

0.03

057.

9070

7.68

607.

5743

6.99

016.

8885

0.10

166.

2255

2B6.

4008

6.73

107.

0206

7.15

520.

1346

7.93

753A

0.00

007.

9375

7.71

65..

.7.

0206

6.94

440.

0762

6.25

603B

6.40

086.

6802

7.02

067.

1196

0.09

917.

9375

5 ⁄ 16–

20or

0.31

25–

20U

N7.

9375

1.27

002A

0.03

057.

9070

7.70

13..

.7.

0815

6.97

740.

1041

6.39

572B

6.55

326.

8580

7.11

207.

2466

0.13

467.

9375

3A0.

0000

7.93

757.

7318

...

7.11

207.

0358

0.07

626.

4262

3B6.

5532

6.80

727.

1120

7.21

360.

1016

7.93

75

5 ⁄ 16–

24or

0.31

25–

24U

NF

7.93

751.

0583

1A0.

0279

7.90

967.

6352

...

7.22

127.

0815

0.13

976.

6497

1B6.

7818

7.03

587.

2492

7.42

950.

1803

7.93

752A

0.02

797.

9096

7.72

67..

.7.

2212

7.12

720.

0940

6.64

972B

6.78

187.

0358

7.24

927.

3711

0.12

197.

9375

3A0.

0000

7.93

757.

7546

...

7.24

927.

1806

0.06

866.

6777

3B6.

7818

6.99

527.

2492

7.34

060.

0914

7.93

75

ASME B1.1-2003 NONMANDATORY APPENDIX C

101

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

(Con

t’d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UNR

Pitc

hDi

amet

eran

dPi

tch

Diam

eter

and

Min

orFu

nctio

nalD

iam

eter

[Not

esFu

nctio

nalD

iam

eter

Diam

eter

,M

ajor

Diam

eter

(4),

(5)]

[Not

es(4

),(5

)]No

min

alSi

zeSe

ries

Max

.M

ajor

Met

ricEq

uiva

lent

sM

inor

Diam

eter

and

Desi

g-Al

low

-M

ax.

Min

.M

ax.

Tole

r-[N

ote

(6)]

Tole

r-Di

amet

er,

Thre

ads/

in.

natio

nDi

a.Pi

tch

Clas

san

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

ance

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

Min

.

5 ⁄ 16–

28or

0.31

25–

28U

N7.

9375

0.90

712A

0.02

547.

9121

7.74

70..

.7.

3228

7.23

390.

0889

6.83

262B

6.95

967.

1628

7.34

827.

4625

0.11

437.

9375

3A0.

0000

7.93

757.

7724

...

7.34

827.

2822

0.06

606.

8580

3B6.

9596

7.12

987.

3482

7.43

460.

0864

7.93

75

5 ⁄ 16–

32or

0.31

25–

32U

NEF

7.93

750.

7938

2A0.

0254

7.91

217.

7597

...

7.39

657.

3127

0.08

386.

9672

2B7.

0866

7.26

447.

4219

7.53

110.

1092

7.93

753A

0.00

007.

9375

7.78

51..

.7.

4219

7.35

840.

0635

6.99

263B

7.08

667.

2288

7.42

197.

5032

0.08

137.

9375

3 ⁄ 8–

16or

0.37

50–

16U

NC

9.52

501.

5875

1A0.

0330

9.49

209.

1313

...

8.46

078.

2956

0.16

517.

6022

1B7.

7978

8.15

348.

4938

8.70

970.

2159

9.52

502A

0.03

309.

4920

9.25

329.

1313

8.46

078.

3490

0.11

187.

6022

2B7.

7978

8.15

348.

4938

8.63

850.

1448

9.52

503A

0.00

009.

5250

9.28

62..

.8.

4938

8.40

990.

0838

7.63

523B

7.79

788.

0823

8.49

388.

6030

0.10

929.

5250

3 ⁄ 8–

20or

0.37

50–

20U

N9.

5250

1.27

002A

0.03

059.

4945

9.28

88..

.8.

6690

8.56

490.

1041

7.98

322B

8.15

348.

4328

8.69

958.

8367

0.13

729.

5250

3A0.

0000

9.52

509.

3193

...

8.69

958.

6208

0.07

878.

0137

3B8.

1534

8.37

448.

6995

8.80

110.

1016

9.52

50

3 ⁄ 8–

24or

0.37

50–

24U

NF

9.52

501.

0583

1A0.

0279

9.49

719.

2227

...

8.80

878.

6639

0.14

488.

2372

1B8.

3820

8.63

608.

8367

9.02

460.

1880

9.52

502A

0.02

799.

4971

9.31

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8087

8.71

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8.23

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8.38

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6360

8.83

678.

9611

0.12

459.

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9.52

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3421

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8.83

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7630

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2652

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3820

8.56

498.

8367

8.93

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0940

9.52

50

3 ⁄ 8–

28or

0.37

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5250

0.90

712A

0.02

799.

4971

9.33

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9078

8.81

630.

0914

8.41

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8.53

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7630

8.93

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9.52

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3599

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8.93

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4455

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5344

8.70

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9357

9.02

460.

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9.52

50

3 ⁄ 8–

32or

0.37

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32U

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9.52

500.

7938

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0254

9.49

969.

3472

...

8.98

408.

8976

0.08

648.

5547

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6614

8.86

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9.12

110.

1118

9.52

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9.37

26..

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0094

8.94

590.

0635

8.58

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8.66

148.

8113

9.00

949.

0932

0.08

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5250

7 ⁄ 16–

14or

0.43

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NC

11.1

125

1.81

431A

0.03

5611

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2..

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8984

9.71

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1803

8.91

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9.14

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5504

9.93

3910

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60.

2337

11.1

125

2A0.

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11.0

769

10.8

153

10.6

832

9.89

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7790

0.11

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9154

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1440

9.55

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9339

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889

0.15

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9339

9.84

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0889

8.95

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9.14

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4412

9.93

3910

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80.

1168

11.1

125

7 ⁄ 16–

16or

0.43

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16U

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5875

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769

10.8

382

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10.0

457

9.92

890.

1168

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337

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9924

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2227

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3980

9.65

2010

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310

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60.

1143

11.1

125

7 ⁄ 16–

20or

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11.1

125

1.27

001A

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510

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6..

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1600

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9.72

8210

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2057

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125

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540

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473

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7282

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330

10.2

870

10.4

242

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0787

9.60

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9.72

829.

9466

10.2

870

10.3

911

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5

7 ⁄ 16–

28or

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125

0.90

712A

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610

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810

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1194

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11.1

125

10.9

474

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10.5

232

10.4

546

0.06

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10.1

346

10.2

895

10.5

232

10.6

121

0.08

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5

7 ⁄ 16–

32or

0.43

75–

32U

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50.

7938

2A0.

0254

11.0

871

10.9

347

...

10.5

715

10.4

851

0.08

6410

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22B

10.2

616

10.4

394

10.5

969

10.7

086

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1811

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0.00

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510

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1..

.10

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910

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80.

0660

10.1

676

3B10

.261

610

.398

810

.596

910

.680

70.

0838

11.1

125




102

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

(Con

t’d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UNR

Pitc

hDi

amet

eran

dPi

tch

Diam

eter

and

Min

orFu

nctio

nalD

iam

eter

[Not

esFu

nctio

nalD

iam

eter

Diam

eter

,M

ajor

Diam

eter

(4),

(5)]

[Not

es(4

),(5

)]No

min

alSi

zeSe

ries

Max

.M

ajor

Met

ricEq

uiva

lent

sM

inor

Diam

eter

and

Desi

g-Al

low

-M

ax.

Min

.M

ax.

Tole

r-[N

ote

(6)]

Tole

r-Di

amet

er,

Thre

ads/

in.

natio

nDi

a.Pi

tch

Clas

san

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

ance

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

Min

.

1 ⁄ 2–

13or

0.50

00–

13U

NC

12.7

000

1.95

381A

0.03

8112

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912

.247

9..

.11

.391

911

.203

90.

1880

10.3

353

1B10

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811

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611

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2464

12.7

000

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0381

12.6

619

12.3

850

12.2

479

11.3

919

11.2

649

0.12

7010

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32B

10.5

918

11.0

236

11.4

300

11.5

951

0.16

5112

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0.00

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012

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1..

.11

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011

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00.

0940

10.3

734

3B10

.591

810

.881

411

.430

011

.551

90.

1219

12.7

000

1 ⁄ 2–

16or

0.50

00–

16U

N12

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01.

5875

2A0.

0356

12.6

644

12.4

257

...

11.6

332

11.5

138

0.11

9410

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72B

10.9

728

11.3

284

11.6

688

11.8

237

0.15

4912

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0.00

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012

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2..

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811

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90.

0889

10.8

102

3B10

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811

.226

811

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811

.785

60.

1168

12.7

000

1 ⁄ 2–

20or

0.50

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20U

NF

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000

1.27

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0.03

3012

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1..

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511

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1626

11.1

557

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411

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811

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512

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90.

2134

12.7

000

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12.6

670

12.4

612

...

11.8

415

11.7

323

0.10

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72B

11.3

284

11.6

078

11.8

745

12.0

167

0.14

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511

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20.

0813

11.1

887

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411

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011

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511

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20.

1067

12.7

000

1 ⁄ 2–

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28U

NEF

12.7

000

0.90

712A

0.02

7912

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112

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0..

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811

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80.

0940

11.5

926

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411

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60.

1219

12.7

000

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0000

12.7

000

12.5

349

...

12.1

107

12.0

396

0.07

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53B

11.7

094

11.8

770

12.1

107

12.2

022

0.09

1412

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0

1 ⁄ 2–

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0.50

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7938

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0254

12.6

746

12.5

222

...

12.1

590

12.0

701

0.08

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72B

11.8

364

12.0

396

12.1

844

12.2

987

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6..

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412

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0660

11.7

551

3B11

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411

.986

312

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412

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70.

0864

12.7

000

9 ⁄ 16–

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0.56

25–

12U

NC

14.2

875

2.11

671A

0.04

0614

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913

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0..

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712

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60.

1981

11.7

272

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812

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413

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40.

2591

14.2

875

2A0.

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14.2

469

13.9

573

13.8

100

12.8

727

12.7

406

0.13

2111

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22B

11.9

888

12.4

460

12.9

134

13.0

861

0.17

2714

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53A

0.00

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513

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9..

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412

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11.7

678

3B11

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812

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212

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413

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90.

1295

14.2

875

9 ⁄ 16–

16or

0.56

25–

16U

N14

.287

51.

5875

2A0.

0356

14.2

519

14.0

132

...

13.2

207

13.1

013

0.11

9412

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22B

12.5

730

12.9

286

13.2

563

13.4

112

0.15

4914

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53A

0.00

0014

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514

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7..

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313

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40.

0889

12.3

977

3B12

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012

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113

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313

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10.

1168

14.2

875

9 ⁄ 16–

18or

0.56

25–

18U

NF

14.2

875

1.41

111A

0.03

5614

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913

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2..

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013

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30.

1727

12.5

705

1B12

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813

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013

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613

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60.

2261

14.2

875

2A0.

0356

14.2

519

14.0

310

...

13.3

350

13.2

207

0.11

4312

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52B

12.7

508

13.0

810

13.3

706

13.5

204

0.14

9914

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53A

0.00

0014

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514

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5..

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613

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20.

0864

12.6

060

3B12

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812

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213

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613

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30.

1118

14.2

875

9 ⁄ 16–

20or

0.56

25–

20U

N14

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51.

2700

2A0.

0330

14.2

545

14.0

487

...

13.4

290

13.3

198

0.10

9212

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22B

12.9

032

13.2

080

13.4

620

13.6

042

0.14

2214

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53A

0.00

0014

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514

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8..

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013

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70.

0813

12.7

762

3B12

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213

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913

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013

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70.

1067

14.2

875

9 ⁄ 16–

24or

0.56

25–

24U

NEF

14.2

875

1.05

832A

0.03

0514

.257

014

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1..

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713

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10.

1016

12.9

972

2B13

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813

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813

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213

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70.

1295

14.2

875

3A0.

0000

14.2

875

14.1

046

...

13.5

992

13.5

230

0.07

6213

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73B

13.1

318

13.3

198

13.5

992

13.6

982

0.09

9114

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5

9 ⁄ 16–

28or

0.56

25–

28U

N14

.287

50.

9071

2A0.

0279

14.2

596

14.0

945

...

13.6

703

13.5

763

0.09

4013

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12B

13.3

096

13.5

128

13.6

982

13.8

201

0.12

1914

.287

53A

0.00

0014

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514

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4..

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.698

213

.627

10.

0711

13.2

080

3B13

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613

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513

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213

.789

70.

0914

14.2

875

9 ⁄ 16–

32or

0.56

25–

32U

N14

.287

50.

7938

2A0.

0279

14.2

596

14.1

072

...

13.7

439

13.6

550

0.08

8913

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72B

13.4

366

13.6

144

13.7

719

13.8

887

0.11

6814

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53A

0.00

0014

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514

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1..

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913

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80.

0660

13.3

426

3B13

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613

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813

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913

.858

20.

0864

14.2

875


103

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

(Con

t’d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UNR

Pitc

hDi

amet

eran

dPi

tch

Diam

eter

and

Min

orFu

nctio

nalD

iam

eter

[Not

esFu

nctio

nalD

iam

eter

Diam

eter

,M

ajor

Diam

eter

(4),

(5)]

[Not

es(4

),(5

)]No

min

alSi

zeSe

ries

Max

.M

ajor

Met

ricEq

uiva

lent

sM

inor

Diam

eter

and

Desi

g-Al

low

-M

ax.

Min

.M

ax.

Tole

r-[N

ote

(6)]

Tole

r-Di

amet

er,

Thre

ads/

in.

natio

nDi

a.Pi

tch

Clas

san

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

ance

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

Min

.

5 ⁄ 8–

11or

0.62

50–

11U

NC

15.8

750

2.30

911A

0.04

3215

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815

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5..

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.333

214

.122

40.

2108

13.0

810

1B13

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813

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414

.376

414

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20.

2718

15.8

750

2A0.

0432

15.8

318

15.5

245

15.3

721

14.3

332

14.1

935

0.13

9713

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02B

13.3

858

13.8

684

14.3

764

14.5

593

0.18

2915

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03A

0.00

0015

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015

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7..

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.376

414

.272

30.

1041

13.1

242

3B13

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813

.693

114

.376

414

.513

60.

1372

15.8

750

5 ⁄ 8–

12or

0.62

50–

12U

N15

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02.

1167

2A0.

0406

15.8

344

15.5

448

...

14.4

602

14.3

231

0.13

7213

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72B

13.5

890

14.0

462

14.5

009

14.6

812

0.18

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015

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4..

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914

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70.

1041

13.3

553

3B13

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013

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014

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914

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50.

1346

15.8

750

5 ⁄ 8–

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0.62

50–

16U

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01.

5875

2A0.

0356

15.8

394

15.6

007

...

14.8

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14.6

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0.12

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14.1

478

14.5

034

14.8

438

15.0

012

0.15

7515

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0.00

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015

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2..

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814

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30.

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13.9

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3B14

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814

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514

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814

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60.

1168

15.8

750

5 ⁄ 8–

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0.62

50–

18U

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15.8

750

1.41

111A

0.03

5615

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415

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7..

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514

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70.

1778

14.1

580

1B14

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014

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214

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115

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20.

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15.8

750

2A0.

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15.8

394

15.6

185

...

14.9

225

14.8

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0.11

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02B

14.3

510

14.6

812

14.9

581

15.1

105

0.15

2415

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015

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0..

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114

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14.1

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3B14

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014

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214

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115

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40.

1143

15.8

750

5 ⁄ 8–

20or

0.62

50–

20U

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01.

2700

2A0.

0330

15.8

420

15.6

362

...

15.0

165

14.9

073

0.10

9214

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72B

14.5

034

14.7

828

15.0

495

15.1

917

0.14

2215

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0.00

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015

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3..

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514

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20.

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14.3

637

3B14

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414

.696

415

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515

.156

20.

1067

15.8

750

5 ⁄ 8–

24or

0.62

50–

24U

NEF

15.8

750

1.05

832A

0.03

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515

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6..

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215

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60.

1016

14.5

847

2B14

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014

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529

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428

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1092

27.6

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828

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428

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60.

1422

30.1

625

13 ⁄ 16–

16or

1.18

75–

16U

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.162

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5875

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0381

30.1

244

29.8

856

...

29.0

932

28.9

636

0.12

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28.4

480

28.8

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29.1

313

29.2

989

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7630

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625

13 ⁄ 16–

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1.41

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0.03

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929

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828

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629

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30.1

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29.9

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29.2

456

29.1

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0.09

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28.6

258

28.8

417

29.2

456

29.3

649

0.11

9430

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5

13 ⁄ 16–

20or

1.18

75–

20U

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51.

2700

2A0.

0356

30.1

269

29.9

212

...

29.3

014

29.1

846

0.11

6828

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28.7

782

29.0

830

29.3

370

29.4

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2430

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529

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28.6

512

3B28

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228

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929

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1143

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625




108

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

(Con

t’d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UNR

Pitc

hDi

amet

eran

dPi

tch

Diam

eter

and

Min

orFu

nctio

nalD

iam

eter

[Not

esFu

nctio

nalD

iam

eter

Diam

eter

,M

ajor

Diam

eter

(4),

(5)]

[Not

es(4

),(5

)]No

min

alSi

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ries

Max

.M

ajor

Met

ricEq

uiva

lent

sM

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eter

and

Desi

g-Al

low

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ax.

Min

.M

ax.

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r-[N

ote

(6)]

Tole

r-Di

amet

er,

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ads/

in.

natio

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san

ce[N

ote

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ote

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e(2

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ance

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.)Cl

ass

Min

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ax.

Min

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ax.

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.

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1.18

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9071

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320

29.9

669

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427

29.4

386

0.10

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29.3

878

29.5

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629

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625

11 ⁄ 4–

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500

3.62

861A

0.05

5931

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929

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60.

3658

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31.6

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31.2

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31.0

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29.3

370

29.1

490

0.18

8027

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28.5

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29.3

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29.6

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3831

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1829

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1750

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0533

31.6

967

31.3

157

31.1

252

29.6

342

29.4

564

0.17

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28.3

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28.9

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29.6

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429

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529

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80.

1753

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500

11 ⁄ 4–

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31.7

500

2.11

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0.04

5731

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3048

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31.7

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31.4

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30.3

301

30.1

727

0.15

7529

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29.4

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29.9

212

30.3

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3231

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29.2

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11 ⁄ 4–

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5875

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31.7

119

31.4

731

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30.6

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30.5

511

0.12

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30.7

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1270

31.7

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11 ⁄ 4–

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31.7

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1.41

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931

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31.5

290

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30.8

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30.7

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1430

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260

30.4

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30.8

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30.9

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11 ⁄ 4–

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31.7

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31.5

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30.8

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30.7

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0.11

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30.3

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30.6

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31.0

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11 ⁄ 4–

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1.25

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9071

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31.7

195

31.5

544

...

31.1

302

31.0

261

0.10

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30.7

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30.9

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31.1

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30.6

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731

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1016

31.7

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15 ⁄ 16–

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1.31

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53.

1750

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0533

33.2

842

32.9

032

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31.2

217

31.0

413

0.18

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29.8

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30.5

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31.2

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31.5

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3733

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931

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1753

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375

15 ⁄ 16–

12or

1.31

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52.

1167

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33.2

943

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31.9

202

31.7

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0.14

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31.0

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31.4

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31.9

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831

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10.

1448

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15 ⁄ 16–

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1.31

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16U

N33

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51.

5875

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33.2

994

33.0

606

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32.2

682

32.1

386

0.12

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31.9

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1270

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375

15 ⁄ 16–

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1.31

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375

1.41

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0.03

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4..

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33.1

165

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32.4

206

32.3

266

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4031

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32.0

167

32.4

206

32.5

425

0.12

1933

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5

15 ⁄ 16–

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1.31

25–

20U

N33

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51.

2700

2A0.

0356

33.3

019

33.0

962

...

32.4

764

32.3

571

0.11

9431

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62B

31.9

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32.2

580

32.5

120

32.6

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4933

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232

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932

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80.

1168

33.3

375


109

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

(Con

t’d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UNR

Pitc

hDi

amet

eran

dPi

tch

Diam

eter

and

Min

orFu

nctio

nalD

iam

eter

[Not

esFu

nctio

nalD

iam

eter

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eter

,M

ajor

Diam

eter

(4),

(5)]

[Not

es(4

),(5

)]No

min

alSi

zeSe

ries

Max

.M

ajor

Met

ricEq

uiva

lent

sM

inor

Diam

eter

and

Desi

g-Al

low

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ax.

Min

.M

ax.

Tole

r-[N

ote

(6)]

Tole

r-Di

amet

er,

Thre

ads/

in.

natio

nDi

a.Pi

tch

Clas

san

ce[N

ote

(2)]

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.[N

ote

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e(2

)]M

in.

ance

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.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

Min

.

15 ⁄ 16–

28or

1.31

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9071

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33.3

070

33.1

419

...

32.7

177

32.6

136

0.10

4132

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32.3

596

32.5

628

32.7

482

32.8

854

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533

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32.2

580

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632

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532

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232

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80.

1016

33.3

375

13 ⁄ 8–

6or

1.37

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NC

34.9

250

4.23

331A

0.06

1034

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034

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6..

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231

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40.

3048

29.8

221

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032

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232

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3937

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250

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640

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34.1

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32.1

132

31.9

100

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1524

29.8

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232

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30.

1981

34.9

250

13 ⁄ 8–

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1.37

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03.

1750

2A0.

0559

34.8

691

34.4

881

34.2

976

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32.6

238

0.18

2931

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32.8

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30.

1778

34.9

250

13 ⁄ 8–

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1.37

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NF

34.9

250

2.11

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0.04

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3124

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34.8

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34.5

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33.5

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33.3

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0.16

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32.6

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33.0

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33.5

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33.7

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933

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933

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1549

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13 ⁄ 8–

16or

1.37

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01.

5875

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34.8

869

34.6

481

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33.8

557

33.7

236

0.13

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33.5

534

33.8

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834

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34.9

250

13 ⁄ 8–

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34.9

250

1.41

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934

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34.7

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34.0

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33.9

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4033

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0

13 ⁄ 8–

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1.37

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2700

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34.8

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34.6

837

...

34.0

639

33.9

446

0.11

9433

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33.5

534

33.8

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433

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434

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534

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1168

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250

13 ⁄ 8–

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1.37

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34.8

945

34.7

294

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34.3

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34.2

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33.9

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734

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734

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30.

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34.9

250

17 ⁄ 16–

6or

1.43

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54.

2333

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0610

36.4

515

35.9

893

...

33.7

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33.4

975

0.20

3231

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31.9

278

32.7

152

33.7

617

34.0

258

0.26

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536

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733

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1524

31.4

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333

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733

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80.

1981

36.5

125

17 ⁄ 16–

8or

1.43

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8U

N36

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53.

1750

2A0.

0559

36.4

566

36.0

756

...

34.3

941

34.2

113

0.18

2932

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12B

33.0

708

33.7

058

34.4

500

34.6

888

0.23

8836

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53A

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536

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1372

32.7

330

3B33

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833

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934

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034

.630

40.

1803

36.5

125

17 ⁄ 16–

12or

1.43

75–

12U

N36

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52.

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114

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

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ads,

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tern

al[N

ote

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Max

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Met

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eter

and

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49.4

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49.6

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49.9

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50.9

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54.3

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56.7

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56.5

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55.0

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54.8

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54.3

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56.8

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56.0

781

55.9

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55.7

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56.1

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119

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56.2

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564

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57.5

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57.2

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57.5

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115

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

(Con

t’d)

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rnal

[Not

e(1

)]In

tern

al[N

ote

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Pitc

hDi

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orFu

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nalD

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eter

[Not

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nalD

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eter

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ajor

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[Not

es(4

),(5

)]No

min

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ries

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ajor

Met

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eter

and

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ax.

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ote

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r-Di

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640

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57.5

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292

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1167

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58.7

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59.2

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1981

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60.6

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750




116

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

(Con

t’d)

Exte

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118

Tabl

eC-

1Li

mit

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Size

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dard

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es(U

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119

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120

Tabl

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1Li

mit

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Size

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2311

97.7

519

2B98

.171

098

.806

099

.537

599

.839

80.

3023

101.

6000

3A0.

0000

101.

6000

101.

2190

...

99.5

375

99.3

648

0.17

2797

.820

53B

98.1

710

98.5

444

99.5

375

99.7

636

0.22

6110

1.60

00

4–12

or4.

0000

–12

UN

101.

6000

2.11

672A

0.05

0810

1.54

9210

1.25

96..

.10

0.17

5110

0.01

000.

1651

99.0

295

2B99

.314

099

.771

210

0.22

5910

0.44

180.

2159

101.

6000

3A0.

0000

101.

6000

101.

3104

...

100.

2259

100.

1014

0.12

4599

.080

33B

99.3

140

99.5

629

100.

2259

100.

3884

0.16

2610

1.60

00

4–16

or4.

0000

–16

UN

101.

6000

1.58

752A

0.04

5710

1.55

4310

1.31

55..

.10

0.52

3010

0.37

320.

1499

99.6

645

2B99

.872

810

0.22

8410

0.56

8810

0.76

180.

1930

101.

6000

3A0.

0000

101.

6000

101.

3612

...

100.

5688

100.

4570

0.11

1899

.710

23B

99.8

728

100.

0989

100.

5688

100.

7135

0.14

4810

1.60

00

41 ⁄ 8–

6or

4.12

50–

6U

N10

4.77

504.

2333

2A0.

0762

104.

6988

104.

2365

...

101.

9480

101.

6940

0.25

4099

.656

92B

100.

2030

100.

9650

102.

0242

102.

3544

0.33

0210

4.77

503A

0.00

0010

4.77

5010

4.31

27..

.10

2.02

4210

1.83

370.

1905

99.7

331

3B10

0.20

3010

0.70

0810

2.02

4210

2.27

060.

2464

104.

7750

41 ⁄ 8–

8or

4.12

50–

8U

N10

4.77

503.

1750

2A0.

0711

104.

7039

104.

3229

...

102.

6414

102.

4077

0.23

3710

0.92

442B

101.

3460

101.

9810

102.

7125

103.

0173

0.30

4810

4.77

503A

0.00

0010

4.77

5010

4.39

40..

.10

2.71

2510

2.53

730.

1753

100.

9955

3B10

1.34

6010

1.71

9410

2.71

2510

2.94

110.

2286

104.

7750

41 ⁄ 8–

12or

4.12

50–

12U

N10

4.77

502.

1167

2A0.

0508

104.

7242

104.

4346

...

103.

3501

103.

1824

0.16

7610

2.20

452B

102.

4890

102.

9462

103.

4009

103.

6168

0.21

5910

4.77

503A

0.00

0010

4.77

5010

4.48

54..

.10

3.40

0910

3.27

640.

1245

102.

2553

3B10

2.48

9010

2.73

7910

3.40

0910

3.56

340.

1626

104.

7750

41 ⁄ 8–

16or

4.12

50–

16U

N10

4.77

501.

5875

2A0.

0457

104.

7293

104.

4905

...

103.

6980

103.

5482

0.14

9910

2.83

952B

103.

0478

103.

4034

103.

7438

103.

9393

0.19

5610

4.77

503A

0.00

0010

4.77

5010

4.53

62..

.10

3.74

3810

3.63

200.

1118

102.

8852

3B10

3.04

7810

3.27

3910

3.74

3810

3.88

850.

1448

104.

7750

41 ⁄ 4–

4or

4.25

00–

4U

N10

7.95

006.

3500

2A0.

0864

107.

8636

107.

2591

...

103.

7387

103.

4466

0.29

2110

0.30

212B

101.

0666

102.

0318

103.

8250

104.

2035

0.37

8510

7.95

003A

0.00

0010

7.95

0010

7.34

55..

.10

3.82

5010

3.60

660.

2184

100.

3884

3B10

1.06

6610

1.83

8810

3.82

5010

4.10

950.

2845

107.

9500

41 ⁄ 4–

6or

4.25

00–

6U

N10

7.95

004.

2333

2A0.

0762

107.

8738

107.

4115

...

105.

1230

104.

8664

0.25

6510

2.83

192B

103.

3780

104.

1400

105.

1992

105.

5319

0.33

2710

7.95

003A

0.00

0010

7.95

0010

7.48

77..

.10

5.19

9210

5.00

870.

1905

102.

9081

3B10

3.37

8010

3.87

5810

5.19

9210

5.44

810.

2489

107.

9500

41 ⁄ 4–

8or

4.25

00–

8U

N10

7.95

003.

1750

2A0.

0711

107.

8789

107.

4979

...

105.

8164

105.

5802

0.23

6210

4.09

942B

104.

5210

105.

1560

105.

8875

106.

1949

0.30

7310

7.95

003A

0.00

0010

7.95

0010

7.56

90..

.10

5.88

7510

5.70

970.

1778

104.

1705

3B10

4.52

1010

4.89

4410

5.88

7510

6.11

610.

2286

107.

9500

41 ⁄ 4–

12or

4.25

00–

12U

N10

7.95

002.

1167

2A0.

0508

107.

8992

107.

6096

...

106.

5251

106.

3574

0.16

7610

5.37

952B

105.

6640

106.

1212

106.

5759

106.

7943

0.21

8410

7.95

003A

0.00

0010

7.95

0010

7.66

04..

.10

6.57

5910

6.45

140.

1245

105.

4303

3B10

5.66

4010

5.91

2910

6.57

5910

6.73

840.

1626

107.

9500

41 ⁄ 4–

16or

4.25

00–

16U

N10

7.95

001.

5875

2A0.

0457

107.

9043

107.

6655

...

106.

8730

106.

7232

0.14

9910

6.01

452B

106.

2228

106.

5784

106.

9188

107.

1143

0.19

5610

7.95

003A

0.00

0010

7.95

0010

7.71

12..

.10

6.91

8810

6.80

700.

1118

106.

0602

3B10

6.22

2810

6.44

8910

6.91

8810

7.06

610.

1473

107.

9500

43 ⁄ 8–

6or

4.37

50–

6U

N11

1.12

504.

2333

2A0.

0762

111.

0488

110.

5865

...

108.

2980

108.

0414

0.25

6510

6.00

692B

106.

5530

107.

3150

108.

3742

108.

7095

0.33

5311

1.12

503A

0.00

0011

1.12

5011

0.66

27..

.10

8.37

4210

8.18

110.

1930

106.

0831

3B10

6.55

3010

7.05

0810

8.37

4210

8.62

560.

2515

111.

1250

43 ⁄ 8–

8or

4.37

50–

8U

N11

1.12

503.

1750

2A0.

0711

111.

0539

110.

6729

...

108.

9914

108.

7552

0.23

6210

7.27

442B

107.

6960

108.

3310

109.

0625

109.

3699

0.30

7311

1.12

503A

0.00

0011

1.12

5011

0.74

40..

.10

9.06

2510

8.88

470.

1778

107.

3455

3B10

7.69

6010

8.06

9410

9.06

2510

9.29

370.

2311

111.

1250


121

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

(Con

t’d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UNR

Pitc

hDi

amet

eran

dPi

tch

Diam

eter

and

Min

orFu

nctio

nalD

iam

eter

[Not

esFu

nctio

nalD

iam

eter

Diam

eter

,M

ajor

Diam

eter

(4),

(5)]

[Not

es(4

),(5

)]No

min

alSi

zeSe

ries

Max

.M

ajor

Met

ricEq

uiva

lent

sM

inor

Diam

eter

and

Desi

g-Al

low

-M

ax.

Min

.M

ax.

Tole

r-[N

ote

(6)]

Tole

r-Di

amet

er,

Thre

ads/

in.

natio

nDi

a.Pi

tch

Clas

san

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

ance

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

Min

.

43 ⁄ 8–

12or

4.37

50–

12U

N11

1.12

502.

1167

2A0.

0508

111.

0742

110.

7846

...

109.

7001

109.

5324

0.16

7610

8.55

452B

108.

8390

109.

2962

109.

7509

109.

9693

0.21

8411

1.12

503A

0.00

0011

1.12

5011

0.83

54..

.10

9.75

0910

9.62

390.

1270

108.

6053

3B10

8.83

9010

9.08

7910

9.75

0910

9.91

340.

1626

111.

1250

43 ⁄ 8–

16or

4.37

50–

16U

N11

1.12

501.

5875

2A0.

0457

111.

0793

110.

8405

...

110.

0480

109.

8982

0.14

9910

9.18

952B

109.

3978

109.

7534

110.

0938

110.

2893

0.19

5611

1.12

503A

0.00

0011

1.12

5011

0.88

62..

.11

0.09

3810

9.97

950.

1143

109.

2352

3B10

9.39

7810

9.62

3911

0.09

3811

0.24

110.

1473

111.

1250

41 ⁄ 2–

4or

4.50

00–

4U

N11

4.30

006.

3500

2A0.

0889

114.

2111

113.

6066

...

110.

0861

109.

7915

0.29

4610

6.64

952B

107.

4166

108.

3818

110.

1750

110.

5586

0.38

3511

4.30

003A

0.00

0011

4.30

0011

3.69

55..

.11

0.17

5010

9.95

410.

2210

106.

7384

3B10

7.41

6610

8.18

8811

0.17

5011

0.46

210.

2870

114.

3000

41 ⁄ 2–

6or

4.50

00–

6U

N11

4.30

004.

2333

2A0.

0787

114.

2213

113.

7590

...

111.

4704

111.

2114

0.25

9110

9.17

942B

109.

7280

110.

4900

111.

5492

111.

8870

0.33

7811

4.30

003A

0.00

0011

4.30

0011

3.83

77..

.11

1.54

9211

1.35

360.

1956

109.

2581

3B10

9.72

8011

0.22

5811

1.54

9211

1.80

060.

2515

114.

3000

41 ⁄ 2–

8or

4.50

00–

8U

N11

4.30

003.

1750

2A0.

0711

114.

2289

113.

8479

...

112.

1664

111.

9276

0.23

8811

0.44

942B

110.

8710

111.

5060

112.

2375

112.

5474

0.30

9911

4.30

003A

0.00

0011

4.30

0011

3.91

90..

.11

2.23

7511

2.05

720.

1803

110.

5205

3B11

0.87

1011

1.24

4411

2.23

7511

2.47

120.

2337

114.

3000

41 ⁄ 2–

12or

4.50

00–

12U

N11

4.30

002.

1167

2A0.

0508

114.

2492

113.

9596

...

112.

8751

112.

7074

0.16

7611

1.72

952B

112.

0140

112.

4712

112.

9259

113.

1443

0.21

8411

4.30

003A

0.00

0011

4.30

0011

4.01

04..

.11

2.92

5911

2.79

890.

1270

111.

7803

3B11

2.01

4011

2.26

2911

2.92

5911

3.09

100.

1651

114.

3000

41 ⁄ 2–

16or

4.50

00–

16U

N11

4.30

001.

5875

2A0.

0457

114.

2543

114.

0155

...

113.

2230

113.

0706

0.15

2411

2.36

452B

112.

5728

112.

9284

113.

2688

113.

4669

0.19

8111

4.30

003A

0.00

0011

4.30

0011

4.06

12..

.11

3.26

8811

3.15

450.

1143

112.

4102

3B11

2.57

2811

2.79

8911

3.26

8811

3.41

610.

1473

114.

3000

45 ⁄ 8–

6or

4.62

50–

6U

N11

7.47

504.

2333

2A0.

0787

117.

3963

116.

9340

...

114.

6454

114.

3838

0.26

1611

2.35

442B

112.

9030

113.

6650

114.

7242

115.

0620

0.33

7811

7.47

503A

0.00

0011

7.47

5011

7.01

27..

.11

4.72

4211

4.52

860.

1956

112.

4331

3B11

2.90

3011

3.40

0811

4.72

4211

4.97

820.

2540

117.

4750

45 ⁄ 8–

8or

4.62

50–

8U

N11

7.47

503.

1750

2A0.

0711

117.

4039

117.

0229

...

115.

3414

115.

1001

0.24

1311

3.62

442B

114.

0460

114.

6810

115.

4125

115.

7249

0.31

2411

7.47

503A

0.00

0011

7.47

5011

7.09

40..

.11

5.41

2511

5.23

220.

1803

113.

6955

3B11

4.04

6011

4.41

9411

5.41

2511

5.64

620.

2337

117.

4750

45 ⁄ 8–

12or

4.62

50–

12U

N11

7.47

502.

1167

2A0.

0508

117.

4242

117.

1346

...

116.

0501

115.

8799

0.17

0211

4.90

452B

115.

1890

115.

6462

116.

1009

116.

3218

0.22

1011

7.47

503A

0.00

0011

7.47

5011

7.18

54..

.11

6.10

0911

5.97

390.

1270

114.

9553

3B11

5.18

9011

5.43

7911

6.10

0911

6.26

600.

1651

117.

4750

45 ⁄ 8–

16or

4.62

50–

16U

N11

7.47

501.

5875

2A0.

0457

117.

4293

117.

1905

...

116.

3980

116.

2456

0.15

2411

5.53

952B

115.

7478

116.

1034

116.

4438

116.

6419

0.19

8111

7.47

503A

0.00

0011

7.47

5011

7.23

62..

.11

6.44

3811

6.32

950.

1143

115.

5852

3B11

5.74

7811

5.97

3911

6.44

3811

6.59

110.

1473

117.

4750

43 ⁄ 4–

4or

4.75

00–

4U

N12

0.65

006.

3500

2A0.

0889

120.

5611

119.

9566

...

116.

4361

116.

1390

0.29

7211

2.99

952B

113.

7666

114.

7318

116.

5250

116.

9137

0.38

8612

0.65

003A

0.00

0012

0.65

0012

0.04

55..

.11

6.52

5011

6.30

150.

2235

113.

0884

3B11

3.76

6611

4.53

8811

6.52

5011

6.81

460.

2896

120.

6500

43 ⁄ 4–

6or

4.75

00–

6U

N12

0.65

004.

2333

2A0.

0787

120.

5713

120.

1090

...

117.

8204

117.

5588

0.26

1611

5.52

942B

116.

0780

116.

8400

117.

8992

118.

2395

0.34

0412

0.65

003A

0.00

0012

0.65

0012

0.18

77..

.11

7.89

9211

7.70

360.

1956

115.

6081

3B11

6.07

8011

6.57

5811

7.89

9211

8.15

570.

2565

120.

6500

43 ⁄ 4–

8or

4.75

00–

8U

N12

0.65

003.

1750

2A0.

0737

120.

5763

120.

1953

...

118.

5139

118.

2726

0.24

1311

6.79

682B

117.

2210

117.

8560

118.

5875

118.

9025

0.31

5012

0.65

003A

0.00

0012

0.65

0012

0.26

90..

.11

8.58

7511

8.40

460.

1829

116.

8705

3B11

7.22

1011

7.59

4411

8.58

7511

8.82

370.

2362

120.

6500




122

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

(Con

t’d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UNR

Pitc

hDi

amet

eran

dPi

tch

Diam

eter

and

Min

orFu

nctio

nalD

iam

eter

[Not

esFu

nctio

nalD

iam

eter

Diam

eter

,M

ajor

Diam

eter

(4),

(5)]

[Not

es(4

),(5

)]No

min

alSi

zeSe

ries

Max

.M

ajor

Met

ricEq

uiva

lent

sM

inor

Diam

eter

and

Desi

g-Al

low

-M

ax.

Min

.M

ax.

Tole

r-[N

ote

(6)]

Tole

r-Di

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5992

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2251

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0549

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2759

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6043

120.

3655

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119.

5730

119.

4206

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8.71

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9228

119.

2784

119.

6188

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8169

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8.92

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9.14

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9.76

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1499

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6500

47 ⁄ 8–

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4.87

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6U

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3.82

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2333

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0787

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7463

123.

2840

...

120.

9954

120.

7313

0.26

4211

8.70

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119.

2530

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121.

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1.07

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7831

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47 ⁄ 8–

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3703

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6889

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4450

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1.76

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0.76

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7742

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122.

4001

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2299

0.17

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1.25

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7793

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7480

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5956

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4.86

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4.93

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126.

6190

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124.

9375

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7521

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126.

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6259

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4989

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124.

7140

124.

9629

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6259

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7935

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127.

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5.76

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2007

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2728

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9688

126.

1186

0.14

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00

51 ⁄ 8–

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6U

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0.17

504.

2333

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0813

130.

0937

129.

6314

...

127.

3429

127.

0762

0.26

6712

5.05

182B

125.

6030

126.

3650

127.

4242

127.

7722

0.34

8013

0.17

503A

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9.71

27..

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7.42

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7.22

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2007

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1331

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6.10

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7.42

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7.68

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2616

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8or

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8U

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0.17

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1750

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130.

1013

129.

7203

...

128.

0389

127.

7925

0.24

6412

6.32

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126.

7460

127.

3810

128.

1125

128.

4351

0.32

2613

0.17

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9.79

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8.11

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7.92

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3955

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6.74

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7.11

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8.11

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8.35

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1750

51 ⁄ 8–

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12U

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0.17

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130.

1242

129.

8346

...

128.

7501

128.

5799

0.17

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7.60

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127.

8890

128.

3462

128.

8009

129.

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9.88

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8.80

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8.67

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6553

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7.88

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8.13

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8.80

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8.96

850.

1676

130.

1750


123

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

(Con

t’d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UNR

Pitc

hDi

amet

eran

dPi

tch

Diam

eter

and

Min

orFu

nctio

nalD

iam

eter

[Not

esFu

nctio

nalD

iam

eter

Diam

eter

,M

ajor

Diam

eter

(4),

(5)]

[Not

es(4

),(5

)]No

min

alSi

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ries

Max

.M

ajor

Met

ricEq

uiva

lent

sM

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Diam

eter

and

Desi

g-Al

low

-M

ax.

Min

.M

ax.

Tole

r-[N

ote

(6)]

Tole

r-Di

amet

er,

Thre

ads/

in.

natio

nDi

a.Pi

tch

Clas

san

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

ance

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

Min

.

51 ⁄ 8–

16or

5.12

50–

16U

N13

0.17

501.

5875

2A0.

0457

130.

1293

129.

8905

...

129.

0980

128.

9431

0.15

4912

8.23

952B

128.

4478

128.

8034

129.

1438

129.

3444

0.20

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0.17

503A

0.00

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0.17

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9.93

62..

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9.14

3812

9.02

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1168

128.

2852

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8.44

7812

8.67

3912

9.14

3812

9.29

360.

1499

130.

1750

51 ⁄ 4–

4or

5.25

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4U

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3.35

006.

3500

2A0.

0914

133.

2586

132.

6540

...

129.

1336

128.

8288

0.30

4812

5.69

702B

126.

4666

127.

4318

129.

2250

129.

6213

0.39

6213

3.35

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3.35

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2.74

55..

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9.22

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8.99

640.

2286

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6.46

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7.23

8812

9.22

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9.52

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133.

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2333

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133.

2687

132.

8064

...

130.

5179

130.

2487

0.26

9212

8.22

682B

128.

7780

129.

5400

130.

5992

130.

9497

0.35

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3.35

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0.00

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3.35

0013

2.88

77..

.13

0.59

9213

0.39

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2007

128.

3081

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8.77

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9.27

5813

0.59

9213

0.86

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2616

133.

3500

51 ⁄ 4–

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5.25

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8U

N13

3.35

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1750

2A0.

0737

133.

2763

132.

8953

...

131.

2139

130.

9649

0.24

8912

9.49

682B

129.

9210

130.

5560

131.

2875

131.

6101

0.32

2613

3.35

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0.00

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3.35

0013

2.96

90..

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1.28

7513

1.10

210.

1854

129.

5705

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9.92

1013

0.29

4413

1.28

7513

1.52

880.

2413

133.

3500

51 ⁄ 4–

12or

5.25

00–

12U

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3.35

002.

1167

2A0.

0508

133.

2992

133.

0096

...

131.

9251

131.

7523

0.17

2713

0.77

952B

131.

0640

131.

5212

131.

9759

132.

1994

0.22

3513

3.35

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0.00

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3.35

0013

3.06

04..

.13

1.97

5913

1.84

630.

1295

130.

8303

3B13

1.06

4013

1.31

2913

1.97

5913

2.14

350.

1676

133.

3500

51 ⁄ 4–

16or

5.25

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16U

N13

3.35

001.

5875

2A0.

0457

133.

3043

133.

0655

...

132.

2730

132.

1181

0.15

4913

1.41

452B

131.

6228

131.

9784

132.

3188

132.

5194

0.20

0713

3.35

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0.00

0013

3.35

0013

3.11

12..

.13

2.31

8813

2.20

190.

1168

131.

4602

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1.62

2813

1.84

8913

2.31

8813

2.46

860.

1499

133.

3500

53 ⁄ 8–

6or

5.37

50–

6U

N13

6.52

504.

2333

2A0.

0813

136.

4437

135.

9814

...

133.

6929

133.

4237

0.26

9213

1.40

182B

131.

9530

132.

7150

133.

7742

134.

1247

0.35

0513

6.52

503A

0.00

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6.52

5013

6.06

27..

.13

3.77

4213

3.57

100.

2032

131.

4831

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1.95

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2.45

0813

3.77

4213

4.03

830.

2642

136.

5250

53 ⁄ 8–

8or

5.37

50–

8U

N13

6.52

503.

1750

2A0.

0762

136.

4488

136.

0678

...

134.

3863

134.

1349

0.25

1513

2.66

932B

133.

0960

133.

7310

134.

4625

134.

7876

0.32

5113

6.52

503A

0.00

0013

6.52

5013

6.14

40..

.13

4.46

2513

4.27

460.

1880

132.

7455

3B13

3.09

6013

3.46

9413

4.46

2513

4.70

640.

2438

136.

5250

53 ⁄ 8–

12or

5.37

50–

12U

N13

6.52

502.

1167

2A0.

0508

136.

4742

136.

1846

...

135.

1001

134.

9273

0.17

2713

3.95

452B

134.

2390

134.

6962

135.

1509

135.

3744

0.22

3513

6.52

503A

0.00

0013

6.52

5013

6.23

54..

.13

5.15

0913

5.02

130.

1295

134.

0053

3B13

4.23

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4.48

7913

5.15

0913

5.31

850.

1676

136.

5250

53 ⁄ 8–

16or

5.37

50–

16U

N13

6.52

501.

5875

2A0.

0457

136.

4793

136.

2405

...

135.

4480

135.

2931

0.15

4913

4.58

952B

134.

7978

135.

1534

135.

4938

135.

6944

0.20

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6.52

503A

0.00

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6.52

5013

6.28

62..

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5.49

3813

5.37

690.

1168

134.

6352

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4.79

7813

5.02

3913

5.49

3813

5.64

620.

1524

136.

5250

51 ⁄ 2–

4or

5.50

00–

4U

N13

9.70

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3500

2A0.

0914

139.

6086

139.

0040

...

135.

4836

135.

1763

0.30

7313

2.04

702B

132.

8166

133.

7818

135.

5750

135.

9764

0.40

1313

9.70

003A

0.00

0013

9.70

0013

9.09

55..

.13

5.57

5013

5.34

390.

2311

132.

1384

3B13

2.81

6613

3.58

8813

5.57

5013

5.87

480.

2997

139.

7000

51 ⁄ 2–

6or

5.50

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6U

N13

9.70

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2333

2A0.

0813

139.

6187

139.

1564

...

136.

8679

136.

5961

0.27

1813

4.57

682B

135.

1280

135.

8900

136.

9492

137.

3022

0.35

3113

9.70

003A

0.00

0013

9.70

0013

9.23

77..

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6.94

9213

6.74

600.

2032

134.

6581

3B13

5.12

8013

5.62

5813

6.94

9213

7.21

330.

2642

139.

7000

51 ⁄ 2–

8or

5.50

00–

8U

N13

9.70

003.

1750

2A0.

0762

139.

6238

139.

2428

...

137.

5613

137.

3099

0.25

1513

5.84

432B

136.

2710

136.

9060

137.

6375

137.

9652

0.32

7713

9.70

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0.00

0013

9.70

0013

9.31

90..

.13

7.63

7513

7.44

960.

1880

135.

9205

3B13

6.27

1013

6.64

4413

7.63

7513

7.88

390.

2464

139.

7000

51 ⁄ 2–

12or

5.50

00–

12U

N13

9.70

002.

1167

2A0.

0508

139.

6492

139.

3596

...

138.

2751

138.

1023

0.17

2713

7.12

952B

137.

4140

137.

8712

138.

3259

138.

5519

0.22

6113

9.70

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0.00

0013

9.70

0013

9.41

04..

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8.32

5913

8.19

630.

1295

137.

1803

3B13

7.41

4013

7.66

2913

8.32

5913

8.49

350.

1676

139.

7000




124

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

(Con

t’d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UNR

Pitc

hDi

amet

eran

dPi

tch

Diam

eter

and

Min

orFu

nctio

nalD

iam

eter

[Not

esFu

nctio

nalD

iam

eter

Diam

eter

,M

ajor

Diam

eter

(4),

(5)]

[Not

es(4

),(5

)]No

min

alSi

zeSe

ries

Max

.M

ajor

Met

ricEq

uiva

lent

sM

inor

Diam

eter

and

Desi

g-Al

low

-M

ax.

Min

.M

ax.

Tole

r-[N

ote

(6)]

Tole

r-Di

amet

er,

Thre

ads/

in.

natio

nDi

a.Pi

tch

Clas

san

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

ance

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

Min

.

51 ⁄ 2–

16or

5.50

00–

16U

N13

9.70

001.

5875

2A0.

0457

139.

6543

139.

4155

...

138.

6230

138.

4681

0.15

4913

7.76

452B

137.

9728

138.

3284

138.

6688

138.

8720

0.20

3213

9.70

003A

0.00

0013

9.70

0013

9.46

12..

.13

8.66

8813

8.55

190.

1168

137.

8102

3B13

7.97

2813

8.19

8913

8.66

8813

8.82

120.

1524

139.

7000

55 ⁄ 8–

6or

5.62

50–

6U

N14

2.87

504.

2333

2A0.

0813

142.

7937

142.

3314

...

140.

0429

139.

7686

0.27

4313

7.75

182B

138.

3030

139.

0650

140.

1242

140.

4798

0.35

5614

2.87

503A

0.00

0014

2.87

5014

2.41

27..

.14

0.12

4213

9.91

840.

2057

137.

8331

3B13

8.30

3013

8.80

0814

0.12

4214

0.39

090.

2667

142.

8750

55 ⁄ 8–

8or

5.62

50–

8U

N14

2.87

503.

1750

2A0.

0762

142.

7988

142.

4178

...

140.

7363

140.

4823

0.25

4013

9.01

932B

139.

4460

140.

0810

140.

8125

141.

1427

0.33

0214

2.87

503A

0.00

0014

2.87

5014

2.49

40..

.14

0.81

2514

0.62

200.

1905

139.

0955

3B13

9.44

6013

9.81

9414

0.81

2514

1.05

890.

2464

142.

8750

55 ⁄ 8–

12or

5.62

50–

12U

N14

2.87

502.

1167

2A0.

0508

142.

8242

142.

5346

...

141.

4501

141.

2773

0.17

2714

0.30

452B

140.

5890

141.

0462

141.

5009

141.

7269

0.22

6114

2.87

503A

0.00

0014

2.87

5014

2.58

54..

.14

1.50

0914

1.37

130.

1295

140.

3553

3B14

0.58

9014

0.83

7914

1.50

0914

1.67

100.

1702

142.

8750

55 ⁄ 8–

16or

5.62

50–

16U

N14

2.87

501.

5875

2A0.

0457

142.

8293

142.

5905

...

141.

7980

141.

6406

0.15

7514

0.93

952B

141.

1478

141.

5034

141.

8438

142.

0470

0.20

3214

2.87

503A

0.00

0014

2.87

5014

2.63

62..

.14

1.84

3814

1.72

690.

1168

140.

9852

3B14

1.14

7814

1.37

3914

1.84

3814

1.99

620.

1524

142.

8750

53 ⁄ 4–

4or

5.75

00–

4U

N14

6.05

006.

3500

2A0.

0940

145.

9560

145.

3515

...

141.

8311

141.

5212

0.30

9913

8.39

442B

139.

1666

140.

1318

141.

9250

142.

3289

0.40

3914

6.05

003A

0.00

0014

6.05

0014

5.44

55..

.14

1.92

5014

1.69

140.

2337

138.

4884

3B13

9.16

6613

9.93

8814

1.92

5014

2.22

730.

3023

146.

0500

53 ⁄ 4–

6or

5.75

00–

6U

N14

6.05

004.

2333

2A0.

0813

145.

9687

145.

5064

...

143.

2179

142.

9436

0.27

4314

0.92

682B

141.

4780

142.

2400

143.

2992

143.

6573

0.35

8114

6.05

003A

0.00

0014

6.05

0014

5.58

77..

.14

3.29

9214

3.09

340.

2057

141.

0081

3B14

1.47

8014

1.97

5814

3.29

9214

3.56

840.

2692

146.

0500

53 ⁄ 4–

8or

5.75

00–

8U

N14

6.05

003.

1750

2A0.

0762

145.

9738

145.

5928

...

143.

9113

143.

6573

0.25

4014

2.19

432B

142.

6210

143.

2560

143.

9875

144.

3177

0.33

0214

6.05

003A

0.00

0014

6.05

0014

5.66

90..

.14

3.98

7514

3.79

700.

1905

142.

2705

3B14

2.62

1014

2.99

4414

3.98

7514

4.23

640.

2489

146.

0500

53 ⁄ 4–

12or

5.75

00–

12U

N14

6.05

002.

1167

2A0.

0533

145.

9967

145.

7071

...

144.

6225

144.

4498

0.17

2714

3.47

702B

143.

7640

144.

2212

144.

6759

144.

9019

0.22

6114

6.05

003A

0.00

0014

6.05

0014

5.76

04..

.14

4.67

5914

4.54

630.

1295

143.

5303

3B14

3.76

4014

4.01

2914

4.67

5914

4.84

600.

1702

146.

0500

53 ⁄ 4–

16or

5.75

00–

16U

N14

6.05

001.

5875

2A0.

0483

146.

0017

145.

7630

...

144.

9705

144.

8130

0.15

7514

4.11

202B

144.

3228

144.

6784

145.

0188

145.

2220

0.20

3214

6.05

003A

0.00

0014

6.05

0014

5.81

12..

.14

5.01

8814

4.90

190.

1168

144.

1602

3B14

4.32

2814

4.54

8914

5.01

8814

5.17

120.

1524

146.

0500

57 ⁄ 8–

6or

5.87

50–

6U

N14

9.22

504.

2333

2A0.

0838

149.

1412

148.

6789

...

146.

3904

146.

1135

0.27

6914

4.09

932B

144.

6530

145.

4150

146.

4742

146.

8349

0.36

0714

9.22

503A

0.00

0014

9.22

5014

8.76

27..

.14

6.47

4214

6.26

590.

2083

144.

1831

3B14

4.65

3014

5.15

0814

6.47

4214

6.74

340.

2692

149.

2250

57 ⁄ 8–

8or

5.87

50–

8U

N14

9.22

503.

1750

2A0.

0762

149.

1488

148.

7678

...

147.

0863

146.

8298

0.25

6514

5.36

932B

145.

7960

146.

4310

147.

1625

147.

4953

0.33

2714

9.22

503A

0.00

0014

9.22

5014

8.84

40..

.14

7.16

2514

6.96

950.

1930

145.

4455

3B14

5.79

6014

6.16

9414

7.16

2514

7.41

140.

2489

149.

2250

57 ⁄ 8–

12or

5.87

50–

12U

N14

9.22

502.

1167

2A0.

0533

149.

1717

148.

8821

...

147.

7975

147.

6223

0.17

5314

6.65

202B

146.

9390

147.

3962

147.

8509

148.

0769

0.22

6114

9.22

503A

0.00

0014

9.22

5014

8.93

54..

.14

7.85

0914

7.71

880.

1321

146.

7053

3B14

6.93

9014

7.18

7914

7.85

0914

8.02

100.

1702

149.

2250

57 ⁄ 8–

16or

5.87

50–

16U

N14

9.22

501.

5875

2A0.

0483

149.

1767

148.

9380

...

148.

1455

147.

9880

0.15

7514

7.28

702B

147.

4978

147.

8534

148.

1938

148.

3995

0.20

5714

9.22

503A

0.00

0014

9.22

5014

8.98

62..

.14

8.19

3814

8.07

690.

1168

147.

3352

3B14

7.49

7814

7.72

3914

8.19

3814

8.34

620.

1524

149.

2250


125

Tabl

eC-

1Li

mit

sof

Size

for

Stan

dard

Seri

es(U

N/U

NR)

Thre

ads,

mm

(Con

t’d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UNR

Pitc

hDi

amet

eran

dPi

tch

Diam

eter

and

Min

orFu

nctio

nalD

iam

eter

[Not

esFu

nctio

nalD

iam

eter

Diam

eter

,M

ajor

Diam

eter

(4),

(5)]

[Not

es(4

),(5

)]No

min

alSi

zeSe

ries

Max

.M

ajor

Met

ricEq

uiva

lent

sM

inor

Diam

eter

and

Desi

g-Al

low

-M

ax.

Min

.M

ax.

Tole

r-[N

ote

(6)]

Tole

r-Di

amet

er,

Thre

ads/

in.

natio

nDi

a.Pi

tch

Clas

san

ce[N

ote

(2)]

Min

.[N

ote

(3)]

[Not

e(2

)]M

in.

ance

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

Min

.

6–4

or6.

0000

–4

UN

152.

4000

6.35

002A

0.09

4015

2.30

6015

1.70

15..

.14

8.18

1114

7.86

610.

3150

144.

7444

2B14

5.51

6614

6.48

1814

8.27

5014

8.68

400.

4089

152.

4000

3A0.

0000

152.

4000

151.

7955

...

148.

2750

148.

0388

0.23

6214

4.83

843B

145.

5166

146.

2888

148.

2750

148.

5798

0.30

4815

2.40

00

6–6

or6.

0000

–6

UN

152.

4000

4.23

332A

0.08

3815

2.31

6215

1.85

39..

.14

9.56

5414

9.28

850.

2769

147.

2743

2B14

7.82

8014

8.59

0014

9.64

9215

0.00

990.

3607

152.

4000

3A0.

0000

152.

4000

151.

9377

...

149.

6492

149.

4409

0.20

8314

7.35

813B

147.

8280

148.

3258

149.

6492

149.

9210

0.27

1815

2.40

00

6–8

or6.

0000

–8

UN

152.

4000

3.17

502A

0.07

6215

2.32

3815

1.94

28..

.15

0.26

1315

0.00

220.

2591

148.

5443

2B14

8.97

1014

9.60

6015

0.33

7515

0.67

280.

3353

152.

4000

3A0.

0000

152.

4000

152.

0190

...

150.

3375

150.

1445

0.19

3014

8.62

053B

148.

9710

149.

3444

150.

3375

150.

5890

0.25

1515

2.40

00

6–12

or6.

0000

–12

UN

152.

4000

2.11

672A

0.05

3315

2.34

6715

2.05

71..

.15

0.97

2515

0.79

730.

1753

149.

8270

2B15

0.11

4015

0.57

1215

1.02

5915

1.25

450.

2286

152.

4000

3A0.

0000

152.

4000

152.

1104

...

151.

0259

150.

8938

0.13

2114

9.88

033B

150.

1140

150.

3629

151.

0259

151.

1960

0.17

0215

2.40

00

6–16

or6.

0000

–16

UN

152.

4000

1.58

752A

0.04

8315

2.35

1715

2.11

30..

.15

1.32

0515

1.16

300.

1575

150.

4620

2B15

0.67

2815

1.02

8415

1.36

8815

1.57

450.

2057

152.

4000

3A0.

0000

152.

4000

152.

1612

...

151.

3688

151.

2494

0.11

9415

0.51

023B

150.

6728

150.

8989

151.

3688

151.

5237

0.15

4915

2.40

00

GEN

ERA

LN

OTE

S:

(a)

Ser

ies

desi

gnat

ion

show

nin

dica

tes

the

UN

thre

adfo

rm;

how

ever

,th

eU

NR

thre

adfo

rmm

aybe

spec

ified

bysu

bsti

tuti

ngU

NR

inpl

ace

ofU

Nin

all

desi

gnat

ions

for

exte

rnal

use

only

.

(b)

Met

ric

valu

esar

eth

ero

unde

d,di

rect

soft

conv

ersi

onof

the

inch

valu

esan

dm

ayno

tm

athe

mat

ical

lyco

mpu

te.

NO

TES

:

(1)

Thre

adcl

asse

sm

aybe

com

bine

d.S

eepa

ra.

4.2.

(2)

For

Clas

s2A

thre

ads

havi

ngan

addi

tive

finis

h,th

em

axim

umm

ajor

and

pitc

hdi

amet

ers,

afte

rco

atin

g,m

ayeq

ual

the

basi

csi

zes,

who

seva

lues

are

the

sam

eas

max

imum

valu

essh

own

for

Clas

s3A

inth

ese

colu

mns

.S

eepa

ra.

4.1.

2.

(3)

For

unfin

ishe

dho

tm

ater

ial,

not

incl

udin

gst

anda

rdfa

sten

ers

wit

hro

lled

thre

ads.

(4)

See

para

.5.

2.1

for

Func

tion

alD

iam

eter

.

(5)

Sin

ceth

ese

tabu

late

dto

lera

nce

valu

esha

vebe

enco

nver

ted

and

then

roun

ded,

they

may

diff

ersl

ight

lyfr

omth

edi

ffer

-en

cebe

twee

nth

eta

bula

ted

max

imum

and

min

imum

valu

es.

(6)

Thes

eva

lues

are

for

refe

renc

eon

ly.

UN

seri

esex

tern

alth

read

max

imum

min

ordi

amet

eris

basi

c(D

1in

para

.11

)fo

rCl

ass

3Aan

dba

sic

min

usal

low

ance

for

Clas

ses

1Aan

d2A

.

(7)

Form

erly

NF.

Not

are

com

men

ded

stan

dard

size

.To

lera

nces

and

allo

wan

ces

are

base

don

one

diam

eter

leng

thof

enga

gem

ent.




126

Tabl

eC-

2Li

mit

sof

Size

for

Sele

cted

Com

bina

tion

sof

UN

S/U

NRS

Seri

esTh

read

s,m

m

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tiona

lDia

met

erFu

nctio

nalD

iam

eter

Dia

met

er,

Met

ric

Maj

orD

iam

eter

[Not

es(3

),(4

)][N

otes

(3),

(4)]

Seri

esM

ax.

Maj

orEq

uiva

lent

sM

inor

Dia

met

erN

omin

alSi

zean

dD

esig

na-

Allo

w-

Max

.M

ax.

Tole

r-[N

ote

(5)]

Tole

r-D

iam

eter

,Th

read

s/in

.tio

nD

ia.

Pitc

hCl

ass

ance

[Not

e(2

)]M

in.

[Not

e(2

)]M

in.

ance

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

Min

.

10–

28or

0.19

0–

28U

NS

4.82

600.

9071

2A0.

0254

4.80

064.

6355

4.21

134.

1275

0.08

383.

7211

2B3.

8354

4.06

404.

2367

4.34

590.

1092

4.82

60

10–

36or

0.19

0–

36U

NS

4.82

600.

7056

2A0.

0229

4.80

314.

6634

4.34

594.

2697

0.07

623.

9624

2B4.

0640

4.24

184.

3688

4.46

790.

0991

4.82

60

10–

40or

0.19

0–

40U

NS

4.82

600.

6350

2A0.

0279

4.79

814.

6152

4.10

974.

0183

0.09

143.

5382

2B3.

6830

3.93

704.

1377

4.25

700.

1194

4.82

60

10–

48or

0.19

0–

48U

NS

4.82

600.

5292

2A0.

0203

4.80

574.

6914

4.46

284.

3967

0.06

604.

1758

2B4.

2418

4.36

884.

4831

4.56

950.

0864

4.82

60

10–

56or

0.19

0–

56U

NS

4.82

600.

4536

2A0.

0178

4.80

824.

7041

4.51

364.

4501

0.06

354.

2672

2B4.

3434

4.44

504.

5314

4.61

260.

0813

4.82

60

12–

36or

0.21

6–

36U

NS

5.48

640.

7056

2A0.

0229

5.46

355.

3238

5.00

634.

9301

0.07

624.

6228

2B4.

7244

4.90

225.

0292

5.12

830.

0991

5.48

64

12–

40or

0.21

6–

40U

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5.48

640.

6350

2A0.

0229

5.46

355.

3340

5.05

214.

9784

0.07

374.

7066

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8006

4.95

305.

0749

5.17

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0965

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48or

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5.48

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8362

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5.02

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5.10

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5.27

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1 ⁄ 4–

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5.76

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6.35

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5.98

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9182

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6.09

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6.03

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9375

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7.73

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7.32

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0.02

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7.77

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7.37

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7.07

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9375

0.63

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9146

7.78

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7.42

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7.15

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8.57

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8.33

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127

Tabl

eC-

2Li

mit

sof

Size

for

Sele

cted

Com

bina

tion

sof

UN

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Seri

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read

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m(C

ont’

d)

Exte

rnal

[Not

e(1

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tern

al[N

ote

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and

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[Not

es(3

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otes

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(4)]

Seri

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ax.

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ia.

Pitc

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ass

ance

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e(2

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in.

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e(2

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ass

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ax.

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ax.

ance

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.

3 ⁄ 8–

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9.49

969.

3599

9.04

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0.08

138.

6589

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7630

8.94

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0678

9.17

450.

1067

9.52

50

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9.52

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6350

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3726

9.09

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7452

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8.99

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1135

9.21

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9.52

50

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9.90

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9.26

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0.09

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9.11

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9.41

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9.90

60

7 ⁄ 16

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4375

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UN

S11

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51.

4111

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0330

11.0

795

10.8

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625

10.0

508

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3980

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5758

9.90

6010

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610

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1448

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125

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4375

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UN

S11

.112

51.

0583

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8222

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9568

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108

10.4

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10.5

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S11

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810

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410

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410

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1219

11.1

125

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12or

0.50

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12.7

000

2.11

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0.04

0612

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412

.369

811

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211

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1372

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397

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1778

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12.7

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12.4

104

11.3

259

11.2

243

0.10

1610

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10.4

140

10.6

299

11.3

259

11.4

579

0.13

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0

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000

1.81

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311

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311

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30.

1270

10.5

004

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211

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211

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411

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50.

1651

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000

1 ⁄ 2–

18or

0.50

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000

1.41

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211

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111

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1473

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000

1 ⁄ 2–

24or

0.50

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12.7

000

1.05

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0.03

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512

.486

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000

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112

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0940

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519

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1219

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000

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5625

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UN

S14

.287

51.

8143

2A0.

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14.2

494

13.9

878

13.0

708

12.9

438

0.12

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12.3

190

12.7

254

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S14

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14.2

596

14.0

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13.6

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13.5

509

0.09

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13.2

588

13.4

874

13.6

754

13.7

998

0.12

4514

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5

5 ⁄ 8–

14or

0.62

5–

14U

NS

15.8

750

1.81

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0.03

8115

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915

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314

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314

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80.

1295

13.6

754

2B13

.919

214

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214

.696

414

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10.

1676

15.8

750

5 ⁄ 8–

27or

0.62

5–

27U

NS

15.8

750

0.94

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0.02

7915

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115

.676

915

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915

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40.

0965

14.7

269

2B14

.859

015

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615

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915

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90.

1270

15.8

750

3 ⁄ 4–

14or

0.75

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14U

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19.0

500

1.81

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0.03

8119

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918

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317

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317

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80.

1295

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504

2B17

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217

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217

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418

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60.

1702

19.0

500

3 ⁄ 4–

18or

0.75

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19.0

500

1.41

112A

0.03

5619

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418

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518

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517

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70.

1168

17.3

330

2B17

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017

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218

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118

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50.

1524

19.0

500

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0.75

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30.

1346

19.0

500

3 ⁄ 4–

27or

0.75

0–

27U

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19.0

500

0.94

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518

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318

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418

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30.

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994

2B18

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618

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918

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40.

1295

19.0

500

7 ⁄ 8–

10or

0.87

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10U

NS

22.2

250

2.54

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0.04

5722

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321

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620

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320

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30.

1549

19.1

541

2B19

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820

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220

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020

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70.

2007

22.2

250




128

Tabl

eC-

2Li

mit

sof

Size

for

Sele

cted

Com

bina

tion

sof

UN

S/U

NRS

Seri

esTh

read

s,m

m(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

UN

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Func

tiona

lDia

met

erFu

nctio

nalD

iam

eter

Dia

met

er,

Met

ric

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orD

iam

eter

[Not

es(3

),(4

)][N

otes

(3),

(4)]

Seri

esM

ax.

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orEq

uiva

lent

sM

inor

Dia

met

erN

omin

alSi

zean

dD

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na-

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ote

(5)]

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eter

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read

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nD

ia.

Pitc

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ass

ance

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e(2

)]M

in.

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e(2

)]M

in.

ance

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.)Cl

ass

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.M

ax.

Min

.M

ax.

ance

Min

.

7 ⁄ 8–

18or

0.87

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18U

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22.2

250

1.41

112A

0.03

5622

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421

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521

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521

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10.

1194

20.5

080

2B20

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021

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221

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121

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00.

1549

22.2

250

7 ⁄ 8–

24or

0.87

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24U

NS

22.2

250

1.05

832A

0.03

0522

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522

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621

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221

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50.

1067

20.9

347

2B21

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021

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021

.536

721

.673

80.

1372

22.2

250

7 ⁄ 8–

27or

0.87

5–

27U

NS

22.2

250

0.94

072A

0.03

0522

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522

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321

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421

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80.

1016

21.0

744

2B21

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021

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621

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921

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90.

1321

22.2

250

1–

10or

1.00

0–

10U

NS

25.4

000

2.54

002A

0.04

5725

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325

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623

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323

.545

80.

1575

22.3

291

2B22

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823

.190

223

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023

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20.

2032

25.4

000

1–

18or

1.00

0–

18U

NS

25.4

000

1.41

112A

0.03

5625

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425

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524

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524

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10.

1194

23.6

830

2B23

.876

024

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224

.483

124

.640

50.

1575

25.4

000

1–

24or

1.00

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24U

NS

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000

1.05

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0.03

3025

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025

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124

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624

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00.

1067

24.1

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2B24

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024

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024

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724

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40.

1397

25.4

000

1–

27or

1.00

0–

27U

NS

25.4

000

0.94

072A

0.03

0525

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525

.199

324

.757

424

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80.

1016

24.2

494

2B24

.384

024

.612

624

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924

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90.

1321

25.4

000

11 ⁄ 8–

10or

1.12

5–

10U

NS

28.5

750

2.54

002A

0.04

8328

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728

.199

126

.875

726

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30.

1575

25.5

016

2B25

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826

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226

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027

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70.

2057

28.5

750

11 ⁄ 8–

14or

1.12

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14U

NS

28.5

750

1.81

432A

0.04

0628

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428

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727

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827

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20.

1346

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2B26

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227

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227

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427

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70.

1753

28.5

750

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28.5

750

1.05

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127

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627

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40.

1092

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821

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027

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027

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90.

1422

28.5

750

11 ⁄ 4–

10or

1.25

0–

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NS

31.7

500

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0.04

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731

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130

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1600

28.6

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2083

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500

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NS

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500

1.81

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0.04

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730

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830

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60.

1372

29.5

478

2B29

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230

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230

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430

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20.

1778

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500

11 ⁄ 4–

24or

1.25

0–

24U

NS

31.7

500

1.05

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0.03

3031

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131

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630

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40.

1092

30.4

571

2B30

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030

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031

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731

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90.

1422

31.7

500

13 ⁄ 8–

10or

1.37

5–

10U

NS

34.9

250

2.54

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0.04

8334

.876

734

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133

.225

733

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70.

1600

31.8

516

2B32

.181

832

.715

233

.274

033

.482

30.

2083

34.9

250

13 ⁄ 8–

14or

1.37

5–

14U

NS

34.9

250

1.81

432A

0.04

0634

.884

434

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733

.705

833

.566

10.

1397

32.7

228

2B32

.969

233

.350

233

.746

433

.926

80.

1803

34.9

250

13 ⁄ 8–

24or

1.37

5–

24U

NS

34.9

250

1.05

832A

0.03

3034

.892

034

.709

134

.203

634

.091

90.

1118

33.6

321

2B33

.782

034

.036

034

.236

734

.381

40.

1448

34.9

250

11 ⁄ 2–

10or

1.50

0–

10U

NS

38.1

000

2.54

002A

0.04

8338

.051

737

.724

136

.400

736

.238

20.

1626

35.0

266

2B35

.356

835

.890

236

.449

036

.659

80.

2108

38.1

000

11 ⁄ 2–

14or

1.50

0–

14U

NS

38.1

000

1.81

432A

0.04

3238

.056

837

.795

236

.878

336

.738

60.

1397

35.8

953

2B36

.144

236

.525

236

.921

437

.104

30.

1829

38.1

000

11 ⁄ 2–

24or

1.50

0–

24U

NS

38.1

000

1.05

832A

0.03

3038

.067

037

.884

137

.378

637

.266

90.

1118

36.8

071

2B36

.957

037

.211

037

.411

737

.559

00.

1473

38.1

000

15 ⁄ 8–

10or

1.62

5–

10U

NS

41.2

750

2.54

002A

0.04

8341

.226

740

.899

139

.575

739

.413

20.

1626

38.2

016

2B38

.531

839

.065

239

.624

039

.834

80.

2108

41.2

750

15 ⁄ 8–

14or

1.62

5–

14U

NS

41.2

750

1.81

432A

0.04

3241

.231

840

.970

240

.053

339

.913

60.

1397

39.0

703

2B39

.319

239

.700

240

.096

440

.279

30.

1829

41.2

750


129

Tabl

eC-

2Li

mit

sof

Size

for

Sele

cted

Com

bina

tion

sof

UN

S/U

NRS

Seri

esTh

read

s,m

m(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tiona

lDia

met

erFu

nctio

nalD

iam

eter

Dia

met

er,

Met

ric

Maj

orD

iam

eter

[Not

es(3

),(4

)][N

otes

(3),

(4)]

Seri

esM

ax.

Maj

orEq

uiva

lent

sM

inor

Dia

met

erN

omin

alSi

zean

dD

esig

na-

Allo

w-

Max

.M

ax.

Tole

r-[N

ote

(5)]

Tole

r-D

iam

eter

,Th

read

s/in

.tio

nD

ia.

Pitc

hCl

ass

ance

[Not

e(2

)]M

in.

[Not

e(2

)]M

in.

ance

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

Min

.

15 ⁄ 8–

24or

1.62

5–

24U

NS

41.2

750

1.05

832A

0.03

3041

.242

041

.059

140

.553

640

.439

30.

1143

39.9

821

2B40

.132

040

.386

040

.586

740

.734

00.

1473

41.2

750

13 ⁄ 4–

10or

1.75

0–

10U

NS

44.4

500

2.54

002A

0.04

8344

.401

744

.074

142

.750

742

.585

60.

1651

41.3

766

2B41

.706

842

.240

242

.799

043

.012

40.

2134

44.4

500

13 ⁄ 4–

14or

1.75

0–

14U

NS

44.4

500

1.81

432A

0.04

3244

.406

844

.145

243

.228

343

.086

00.

1422

42.2

453

2B42

.494

242

.875

243

.271

443

.456

90.

1854

44.4

500

13 ⁄ 4–

18or

1.75

0–

18U

NS

44.4

500

1.41

112A

0.03

8144

.411

944

.190

943

.495

043

.365

40.

1295

42.7

304

2B42

.926

043

.256

243

.533

143

.700

70.

1676

44.4

500

17 ⁄ 8–

10or

1.87

5–

10U

NS

47.6

250

2.54

002A

0.05

0847

.574

247

.246

545

.923

245

.758

10.

1651

44.5

491

2B44

.881

845

.415

245

.974

046

.189

90.

2159

47.6

250

17 ⁄ 8–

14or

1.87

5–

14U

NS

47.6

250

1.81

432A

0.04

3247

.581

847

.320

246

.403

346

.261

00.

1422

45.4

203

2B45

.669

246

.050

246

.446

446

.631

90.

1854

47.6

250

17 ⁄ 8–

18or

1.87

5–

18U

NS

47.6

250

1.41

112A

0.03

8147

.586

947

.365

946

.670

046

.540

40.

1295

45.9

054

2B46

.101

046

.431

246

.708

146

.875

70.

1676

47.6

250

2–

10or

2.00

0–

10U

NS

50.8

000

2.54

002A

0.05

0850

.749

250

.421

549

.098

248

.933

10.

1651

47.7

241

2B48

.056

848

.590

249

.149

049

.364

90.

2159

50.8

000

2–

14or

2.00

0–

14U

NS

50.8

000

1.81

432A

0.04

3250

.756

850

.495

249

.578

349

.433

50.

1448

48.5

953

2B48

.844

249

.225

249

.621

449

.809

40.

1880

50.8

000

2–

18or

2.00

0–

18U

NS

50.8

000

1.41

112A

0.03

8150

.761

950

.540

949

.845

049

.715

40.

1295

49.0

804

2B49

.276

049

.606

249

.883

150

.053

20.

1702

50.8

000

21 ⁄ 16

–16

or2.

0625

–16

UN

S52

.387

51.

5875

2A0.

0406

52.3

469

52.1

081

51.3

156

51.1

785

0.13

7250

.457

12B

50.6

730

51.0

286

51.3

563

51.5

341

0.17

7852

.387

53A

0.00

0052

.387

552

.148

751

.356

351

.254

70.

1016

50.4

977

3B50

.673

050

.886

451

.356

351

.490

90.

1346

52.3

875

23 ⁄ 16

–16

or2.

1875

–16

UN

S55

.562

51.

5875

2A0.

0406

55.5

219

55.2

831

54.4

906

54.3

535

0.13

7253

.632

12B

53.8

480

54.2

036

54.5

313

54.7

116

0.18

0355

.562

53A

0.00

0055

.562

555

.323

754

.531

354

.427

10.

1041

53.6

727

3B53

.848

054

.061

454

.531

354

.665

90.

1346

55.5

625

21 ⁄ 4–

10or

2.25

0–

10U

NS

57.1

500

2.54

002A

0.05

0857

.099

256

.771

555

.448

255

.280

60.

1676

54.0

741

2B54

.406

854

.940

255

.499

055

.717

40.

2184

57.1

500

21 ⁄ 4–

14or

2.25

0–

14U

NS

57.1

500

1.81

432A

0.04

3257

.106

856

.845

255

.928

355

.780

90.

1473

54.9

453

2B55

.194

255

.575

255

.971

456

.161

90.

1905

57.1

500

21 ⁄ 4–

18or

2.25

0–

18U

NS

57.1

500

1.41

112A

0.04

0657

.109

456

.888

456

.192

456

.060

30.

1321

55.4

279

2B55

.626

055

.956

256

.233

156

.405

80.

1727

57.1

500

25 ⁄ 16

–16

or2.

3125

–16

UN

S58

.737

51.

5875

2A0.

0406

58.6

969

58.4

581

57.6

656

57.5

259

0.13

9756

.807

12B

57.0

230

57.3

786

57.7

063

57.8

866

0.18

0358

.737

53A

0.00

0058

.737

558

.498

757

.706

357

.602

10.

1041

56.8

477

3B57

.023

057

.236

457

.706

357

.840

90.

1346

58.7

375

27 ⁄ 16

–16

or2.

4375

–16

UN

S61

.912

51.

5875

2A0.

0432

61.8

693

61.6

306

60.8

381

60.6

984

0.13

9759

.979

62B

60.1

980

60.5

536

60.8

813

61.0

641

0.18

2961

.912

53A

0.00

0061

.912

561

.673

760

.881

360

.777

10.

1041

60.0

227

3B60

.198

060

.411

460

.881

361

.018

40.

1372

61.9

125

21 ⁄ 2–

10or

2.50

0–

10U

NS

63.5

000

2.54

002A

0.05

0863

.449

263

.121

561

.798

261

.628

00.

1702

60.4

241

2B60

.756

861

.290

261

.849

062

.070

00.

2210

63.5

000

21 ⁄ 2–

14or

2.50

0–

14U

NS

63.5

000

1.81

432A

0.04

3263

.456

863

.195

262

.278

362

.130

90.

1473

61.2

953

2B61

.544

261

.925

262

.321

462

.514

50.

1930

63.5

000




130

Tabl

eC-

2Li

mit

sof

Size

for

Sele

cted

Com

bina

tion

sof

UN

S/U

NRS

Seri

esTh

read

s,m

m(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tiona

lDia

met

erFu

nctio

nalD

iam

eter

Dia

met

er,

Met

ric

Maj

orD

iam

eter

[Not

es(3

),(4

)][N

otes

(3),

(4)]

Seri

esM

ax.

Maj

orEq

uiva

lent

sM

inor

Dia

met

erN

omin

alSi

zean

dD

esig

na-

Allo

w-

Max

.M

ax.

Tole

r-[N

ote

(5)]

Tole

r-D

iam

eter

,Th

read

s/in

.tio

nD

ia.

Pitc

hCl

ass

ance

[Not

e(2

)]M

in.

[Not

e(2

)]M

in.

ance

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

Min

.

21 ⁄ 2–

18or

2.50

0–

18U

NS

63.5

000

1.41

112A

0.04

0663

.459

463

.238

462

.542

462

.407

80.

1346

61.7

779

2B61

.976

062

.306

262

.583

162

.758

30.

1753

63.5

000

23 ⁄ 4–

10or

2.75

0–

10U

NS

69.8

500

2.54

002A

0.05

0869

.799

269

.471

568

.148

267

.975

50.

1727

66.7

741

2B67

.106

867

.640

268

.199

068

.422

50.

2235

69.8

500

23 ⁄ 4–

14or

2.75

0–

14U

NS

69.8

500

1.81

432A

0.04

5769

.804

369

.542

768

.625

768

.475

90.

1499

67.6

427

2B67

.894

268

.275

268

.671

468

.867

00.

1956

69.8

500

23 ⁄ 4–

18or

2.75

0–

18U

NS

69.8

500

1.41

112A

0.04

0669

.809

469

.588

468

.892

468

.757

80.

1346

68.1

279

2B68

.326

068

.656

268

.933

169

.110

90.

1778

69.8

500

3–

10or

3.00

0–

10U

NS

76.2

000

2.54

002A

0.05

0876

.149

275

.821

574

.498

274

.325

50.

1727

73.1

241

2B73

.456

873

.990

274

.549

074

.775

10.

2261

76.2

000

3–

14or

3.00

0–

14U

NS

76.2

000

1.81

432A

0.04

5776

.154

375

.892

774

.975

774

.825

90.

1499

73.9

927

2B74

.244

274

.625

275

.021

475

.217

00.

1956

76.2

000

3–

18or

3.00

0–

18U

NS

76.2

000

1.41

112A

0.04

0676

.159

475

.938

475

.242

475

.105

30.

1372

74.4

779

2B74

.676

075

.006

275

.283

175

.460

90.

1778

76.2

000

31 ⁄ 4–

10or

3.25

0–

10U

NS

82.5

500

2.54

002A

0.05

3382

.496

782

.169

080

.845

780

.670

40.

1753

79.4

715

2B79

.806

880

.340

280

.899

081

.125

10.

2261

82.5

500

31 ⁄ 4–

14or

3.25

0–

14U

NS

82.5

500

1.81

432A

0.04

5782

.504

382

.242

781

.325

781

.173

30.

1524

80.3

427

2B80

.594

280

.975

281

.371

481

.569

60.

1981

82.5

500

31 ⁄ 4–

18or

3.25

0–

18U

NS

82.5

500

1.41

112A

0.04

0682

.509

482

.288

481

.592

481

.452

70.

1397

80.8

279

2B81

.026

081

.356

281

.633

181

.813

40.

1803

82.5

500

31 ⁄ 2–

10or

3.50

0–

10U

NS

88.9

000

2.54

002A

0.05

3388

.846

788

.519

087

.195

787

.020

40.

1753

85.8

215

2B86

.156

886

.690

287

.249

087

.477

60.

2286

88.9

000

31 ⁄ 2–

14or

3.50

0–

14U

NS

88.9

000

1.81

432A

0.04

5788

.854

388

.592

787

.675

787

.520

80.

1549

86.6

927

2B86

.944

287

.325

287

.721

487

.922

10.

2007

88.9

000

31 ⁄ 2–

18or

3.50

0–

18U

NS

88.9

000

1.41

112A

0.04

3288

.856

888

.635

887

.939

987

.800

20.

1397

87.1

753

2B87

.376

087

.706

287

.983

188

.165

90.

1829

88.9

000

33 ⁄ 4–

10or

3.75

0–

10U

NS

95.2

500

2.54

002A

0.05

3395

.196

794

.869

093

.545

793

.367

90.

1778

92.1

715

2B92

.506

893

.040

293

.599

093

.830

10.

2311

95.2

500

33 ⁄ 4–

14or

3.75

0–

14U

NS

95.2

500

1.81

432A

0.04

5795

.204

394

.942

794

.025

793

.870

80.

1549

93.0

427

2B93

.294

293

.675

294

.071

494

.272

10.

2007

95.2

500

33 ⁄ 4–

18or

3.75

0–

18U

NS

95.2

500

1.41

112A

0.04

3295

.206

894

.985

894

.289

994

.147

60.

1422

93.5

253

2B93

.726

094

.056

294

.333

194

.515

90.

1829

95.2

500

4–

10or

4.00

0–

10U

NS

101.

6000

2.54

002A

0.05

3310

1.54

6710

1.21

9099

.895

799

.717

90.

1778

98.5

215

2B98

.856

899

.390

299

.949

010

0.18

010.

2311

101.

6000

4–

14or

4.00

0–

14U

NS

101.

6000

1.81

432A

0.04

5710

1.55

4310

1.29

2710

0.37

5710

0.21

820.

1575

99.3

927

2B99

.644

210

0.02

5210

0.42

1410

0.62

460.

2032

101.

6000

41 ⁄ 4–

10or

4.25

0–

10U

NS

107.

9500

2.54

002A

0.05

3310

7.89

6710

7.56

9010

6.24

5710

6.06

530.

1803

104.

8715

2B10

5.20

6810

5.74

0210

6.29

9010

6.53

270.

2337

107.

9500

41 ⁄ 4–

14or

4.25

0–

14U

NS

107.

9500

1.81

432A

0.04

8310

7.90

1710

7.64

0110

6.72

3210

6.56

570.

1575

105.

7402

2B10

5.99

4210

6.37

5210

6.77

1410

6.97

720.

2057

107.

9500

41 ⁄ 2–

10or

4.50

0–

10U

NS

114.

3000

2.54

002A

0.05

3311

4.24

6711

3.91

9011

2.59

5711

2.41

530.

1803

111.

2215

2B11

1.55

6811

2.09

0211

2.64

9011

2.88

520.

2362

114.

3000


131

Tabl

eC-

2Li

mit

sof

Size

for

Sele

cted

Com

bina

tion

sof

UN

S/U

NRS

Seri

esTh

read

s,m

m(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

UN

RM

inor

Func

tiona

lDia

met

erFu

nctio

nalD

iam

eter

Dia

met

er,

Met

ric

Maj

orD

iam

eter

[Not

es(3

),(4

)][N

otes

(3),

(4)]

Seri

esM

ax.

Maj

orEq

uiva

lent

sM

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met

erN

omin

alSi

zean

dD

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na-

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w-

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r-[N

ote

(5)]

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eter

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read

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ia.

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ass

ance

[Not

e(2

)]M

in.

[Not

e(2

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in.

ance

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

ance

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.

41 ⁄ 2–

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3000

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120.

6500

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6500

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10or

5.00

0–

10U

NS

127.

0000

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4112

6.61

6512

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3112

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020.

1829

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2B12

4.25

6812

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0212

5.34

9012

5.58

780.

2388

127.

0000

5–

14or

5.00

0–

14U

NS

127.

0000

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432A

0.04

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5.61

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1626

124.

7902

2B12

5.04

4212

5.42

5212

5.82

1412

6.03

230.

2108

127.

0000

51 ⁄ 4–

10or

5.25

0–

10U

NS

133.

3500

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0.05

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4113

2.96

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1.64

3113

1.45

770.

1854

130.

2690

2B13

0.60

6813

1.14

0213

1.69

9013

1.93

780.

2388

133.

3500

51 ⁄ 4–

14or

5.25

0–

14U

NS

133.

3500

1.81

432A

0.04

8313

3.30

1713

3.04

0113

2.12

3213

1.96

060.

1626

131.

1402

2B13

1.39

4213

1.77

5213

2.17

1413

2.38

230.

2108

133.

3500

51 ⁄ 2–

10or

5.50

0–

10U

NS

139.

7000

2.54

002A

0.05

5913

9.64

4113

9.31

6513

7.99

3113

7.80

770.

1854

136.

6190

2B13

6.95

6813

7.49

0213

8.04

9013

8.29

030.

2413

139.

7000

51 ⁄ 2–

14or

5.50

0–

14U

NS

139.

7000

1.81

432A

0.04

8313

9.65

1713

9.39

0113

8.47

3213

8.31

060.

1626

137.

4902

2B13

7.74

4213

8.12

5213

8.52

1413

8.73

480.

2134

139.

7000

53 ⁄ 4–

10or

5.75

0–

10U

NS

146.

0500

2.54

002A

0.05

5914

5.99

4114

5.66

6514

4.34

3114

4.15

770.

1854

142.

9690

2B14

3.30

6814

3.84

0214

4.39

9014

4.64

030.

2413

146.

0500

53 ⁄ 4–

14or

5.75

0–

14U

NS

146.

0500

1.81

432A

0.04

8314

6.00

1714

5.74

0114

4.82

3214

4.65

810.

1651

143.

8402

2B14

4.09

4214

4.47

5214

4.87

1414

5.08

480.

2134

146.

0500

6–

10or

6.00

0–

10U

NS

152.

4000

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6515

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3115

0.50

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1880

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4000

6–

14or

6.00

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14U

NS

152.

4000

1.81

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1651

150.

1877

2B15

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0.82

5215

1.22

1415

1.43

730.

2159

152.

4000

GEN

ERA

LN

OTE

:S

erie

sde

sign

atio

nsh

own

indi

cate

sth

eU

Nth

read

form

;ho

wev

er,

the

UN

Rth

read

form

may

besp

ecifi

edby

subs

titu

ting

UN

Rin

plac

eof

UN

inal

lde

sign

atio

nsfo

rex

tern

alus

eon

ly.

NO

TES

:(1

)Th

read

clas

ses

may

beco

mbi

ned.

See

para

.4.

2.(2

)Fo

rCl

ass

2Ath

read

sha

ving

anad

diti

vefin

ish,

the

max

imum

maj

oran

dpi

tch

diam

eter

s,af

ter

coat

ing,

may

equa

lth

eba

sic

size

s,w

hose

valu

esar

eth

esa

me

asm

axim

umva

lues

show

nfo

rCl

ass

3Ain

thes

eco

lum

ns.

See

para

.4.

1.2.

(3)

See

para

.5.

2.1

for

Func

tion

alD

iam

eter

.(4

)S

ince

thes

eta

bula

ted

tole

ranc

eva

lues

have

been

conv

erte

dan

dth

enro

unde

d,th

eym

aydi

ffer

slig

htly

from

the

diff

er-

ence

betw

een

the

tabu

late

dm

axim

uman

dm

inim

umva

lues

.(5

)Th

ese

valu

esar

efo

rre

fere

nce

only

.U

Nse

ries

exte

rnal

thre

adm

axim

umm

inor

diam

eter

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sic

(D1

inpa

ra.

11)

for

Clas

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cm

inus

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wan

cefo

rCl

asse

s1A

and

2A.





Table C-3 Thread Form Data, mm

0.1875H[Note (1)]

0.2500HTruncation of0.1250H [Note (1)]UNR Design[Note (1)] Profile External

Basic Flat at Flat at Truncation of External Thread Root0.1667HInternal Internal Internal Thread Root and

H [Note (1)]Thread Crest, Thread Root Thread Root and Half Truncation of[Note (1)]and External and External and External External Addendum of Internal

UN Thread Thread Crest, Height of Thread Crest, Thread Root External Thread Crest,Root, Frs p Frn p Fcs p Sharp frn p fes p Full Radius, Thread, frs p fcn p

Threads/ Fcn p P/4 p P/8 p V-Thread p 0.10825318P Max., rrs p Srs p 0.21650635Pin. Pitch, P 0.25000000P 0.12500000P 0.86602540P [Note (2)] 0.14433757P 0.16237976P [Note (3)]

1 2 3 4 5 6 7 8 9

80 0.31750 0.0794 0.0397 0.2750 0.0344 0.0458 0.0516 0.068772 0.35278 0.0882 0.0441 0.3055 0.0382 0.0509 0.0573 0.076464 0.39688 0.0992 0.0496 0.3437 0.0430 0.0573 0.0644 0.085956 0.45357 0.1134 0.0567 0.3928 0.0491 0.0655 0.0737 0.098248 0.52917 0.1323 0.0661 0.4583 0.0573 0.0764 0.0859 0.114644 0.57727 0.1443 0.0722 0.4999 0.0625 0.0833 0.0937 0.1250

40 0.63500 0.1588 0.0794 0.5499 0.0687 0.0916 0.1031 0.137536 0.70556 0.1764 0.0882 0.6110 0.0764 0.1018 0.1146 0.152832 0.79375 0.1985 0.0992 0.6874 0.0859 0.1146 0.1289 0.171928 0.90714 0.2268 0.1134 0.7856 0.0982 0.1309 0.1473 0.196427 0.94074 0.2352 0.1176 0.8147 0.1018 0.1358 0.1528 0.203724 1.05833 0.2646 0.1323 0.9165 0.1146 0.1528 0.1719 0.2291

20 1.27000 0.3175 0.1588 1.0998 0.1375 0.1833 0.2062 0.275018 1.41111 0.3528 0.1764 1.2221 0.1528 0.2037 0.2291 0.305516 1.58750 0.3969 0.1985 1.3748 0.1719 0.2291 0.2578 0.343714 1.81429 0.4536 0.2268 1.5712 0.1964 0.2619 0.2946 0.392813 1.95385 0.4885 0.2442 1.6921 0.2115 0.2820 0.3173 0.423012 2.11667 0.5292 0.2646 1.8331 0.2291 0.3055 0.3437 0.4583

11.5 2.20870 0.5522 0.2761 1.9128 0.2391 0.3188 0.3586 0.478211 2.30909 0.5773 0.2886 1.9997 0.2500 0.3333 0.3750 0.499910 2.54000 0.6350 0.3175 2.1997 0.2750 0.3666 0.4124 0.5499

9 2.82222 0.7056 0.3528 2.4441 0.3055 0.4074 0.4583 0.61108 3.17500 0.7938 0.3969 2.7496 0.3437 0.4583 0.5155 0.6874

7 3.62857 0.9071 0.4536 3.1424 0.3928 0.5237 0.5892 0.78566 4.23333 1.0583 0.5292 3.6662 0.4583 0.6110 0.6874 0.91655 5.08000 1.2700 0.6350 4.3994 0.5499 0.7332 0.8249 1.09984.5 5.64444 1.4111 0.7056 4.8882 0.6110 0.8147 0.9165 1.22214 6.35000 1.5875 0.7938 5.4993 0.6874 0.9165 1.0311 1.3748

132


Table C-3 Thread Form Data, mm (Cont’d)

0.625H[Note (1)]

Height of0.9167H 1.2500HInternal[Note (1)] [Note (1)]Thread, UN

0.375H 0.7500H 1.3750HExternal Difference Double[Note (1)] [Note (1)] [Note (1)]Thread, and Between Height of

0.6875HAddendum Depth of Twice the Max. Major Internal Double[Note (1)]of External Thread External and Pitch Thread and Height of

Thread, Engagement, Height of Thread Diameters of External UN External UNR0.5000Hhas p hs p hn p UNR External Addendum, Internal Thread, Thread,[Note (1)]Threads/ 0.32475953P he p Thread, hs p hb p 2has p Thread p 2hn p 2hs p

in. [Note (4)] 0.54126588P 0.59539247P 0.64951905P 0.79385662P 1.08253175P 1.19078493P 0.43301270P

1 10 11 12 13 14 15 16 17

80 0.1031 0.1719 0.1890 0.2062 0.2520 0.3437 0.3781 0.137572 0.1146 0.1910 0.2100 0.2291 0.2801 0.3819 0.4201 0.152864 0.1289 0.2148 0.2363 0.2578 0.3151 0.4296 0.4726 0.171956 0.1473 0.2455 0.2701 0.2946 0.3601 0.4910 0.5401 0.196448 0.1719 0.2864 0.3151 0.3437 0.4201 0.5728 0.6301 0.229144 0.1875 0.3124 0.3437 0.3750 0.4583 0.6249 0.6874 0.2500

40 0.2062 0.3437 0.3781 0.4124 0.5041 0.6874 0.7562 0.275036 0.2291 0.3819 0.4201 0.4583 0.5601 0.7638 0.8402 0.305532 0.2578 0.4296 0.4726 0.5155 0.6301 0.8593 0.9452 0.343728 0.2946 0.4910 0.5401 0.5892 0.7201 0.9820 1.0802 0.392827 0.3055 0.5092 0.5601 0.6110 0.7468 1.0184 1.1202 0.407424 0.3437 0.5728 0.6301 0.6874 0.8402 1.1457 1.2602 0.4583

20 0.4124 0.6874 0.7562 0.8249 1.0082 1.3748 1.5123 0.549918 0.4583 0.7638 0.8402 0.9165 1.1202 1.5276 1.6803 0.611016 0.5155 0.8593 0.9452 1.0311 1.2602 1.7185 1.8904 0.687414 0.5892 0.9820 1.0802 1.1784 1.4403 1.9640 2.1604 0.785613 0.6345 1.0576 1.1633 1.2691 1.5511 2.1151 2.3266 0.846012 0.6874 1.1457 1.2602 1.3748 1.6803 2.2914 2.5205 0.9165

11.5 0.7173 1.1955 1.3150 1.4346 1.7534 2.3910 2.6301 0.956411 0.7499 1.2498 1.3748 1.4998 1.8331 2.4997 2.7496 0.999910 0.8249 1.3748 1.5123 1.6498 2.0164 2.7496 3.0246 1.0998

9 0.9165 1.5276 1.6803 1.8331 2.2404 3.0551 3.3606 1.22218 1.0311 1.7185 1.8904 2.0622 2.5205 3.4370 3.7807 1.3748

7 1.1784 1.9640 2.1604 2.3568 2.8806 3.9280 4.3208 1.57126 1.3748 2.2914 2.5205 2.7496 3.3606 4.5827 5.0410 1.83315 1.6498 2.7496 3.0246 3.2996 4.0328 5.4993 6.0492 2.19974.5 1.8331 3.0551 3.3606 3.6662 4.4809 6.1103 6.7213 2.44414 2.0622 3.4370 3.7807 4.1245 5.0410 6.8741 7.5615 2.7496

GENERAL NOTES:

(a) All dimensions are in millimeters (except for threads per inch, col. 1).(b) Metric values are the rounded, direct soft conversion of the inch values and do not comply to ASME B1.30 and may

not mathematically compute. They should be used for reference only.(c) All thread calculations are to be performed using a function of pitch (P); the use of thread height (H) is for reference

only as stated in ASME B1.30.

NOTES:(1) The thread values based on a function of height “H” are used for reference only.

(2) The values tabulated in col. 6 also pertain to the minimum root radius of UNR screw threads. See paras. 2.3.1 and2.3.1(a).

(3) han p fcn p 0.25H p 0.21650635P

(4) hdn p has p 0.375H p 0.32475953P

133



ASME B1.1-2003

NONMANDATORY APPENDIX DSPECIAL THREADS

Newly created special thread dimensions shall bedetermined by use of the formulas in the body of thisstandard and the employment of the rounding rules setforth by ASME B1.30.

Existing special thread dimensions developed fromprevious editions of B1.1 and using rounding rules otherthan those contained in B1.30 may differ. Previouslyestablished special thread dimensions are acceptable forcontinued use.

134

This Appendix contains Table D-1 (formerly Table 3Bin B1.1-1989) which contains tabulated values for manyof the more commonly used nonstandard thread sizes.Also contained are Tables D-2 through D-11 (formerlyTables 31 through 40 in B1.1-1989). These tables wereused in the past to calculate special thread sizes.

NONMANDATORY APPENDIX D ASME B1.1-2003

Tabl

eD

-1Li

mit

sof

Size

for

Sele

cted

Com

bina

tion

sof

UN

S/U

NRS

Seri

esTh

read

s

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UN

RPi

tch

Dia

met

eran

dM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(3

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(3)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Max

.To

lera

nce

[Not

e(5

)]D

iam

eter

,Th

read

s/in

.na

tion

Clas

sA

llow

ance

[Not

e(2

)]M

in.

[Not

e(2

)]M

in.

[Not

e(4

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(6)

10–

28or

0.19

0–

28U

NS

2A0.

0010

0.18

900.

1825

0.16

580.

1625

0.00

3339

0.14

652B

0.15

10.

160

0.16

680.

1711

0.00

430.

1900

(6)

10–

36or

0.19

0–

36U

NS

2A0.

0009

0.18

910.

1836

0.17

110.

1681

0.00

2988

0.15

602B

0.16

00.

167

0.17

200.

1759

0.00

390.

1900

(6)

10–

40or

0.19

0–

40U

NS

2A0.

0009

0.18

910.

1840

0.17

290.

1700

0.00

2856

0.15

932B

0.16

30.

169

0.17

380.

1775

0.00

370.

1900

10–

48or

0.19

0–

48U

NS

2A0.

0008

0.18

920.

1847

0.17

570.

1731

0.00

2648

0.16

442B

0.16

70.

172

0.17

650.

1799

0.00

340.

1900

(6)

10–

56or

0.19

0–

56U

NS

2A0.

0007

0.18

930.

1852

0.17

770.

1752

0.00

2488

0.16

802B

0.17

10.

175

0.17

840.

1816

0.00

320.

1900

(6)

12–

36or

0.21

6–

36U

NS

2A0.

0009

0.21

510.

2096

0.19

710.

1941

0.00

3026

0.18

202B

0.18

60.

193

0.19

800.

2019

0.00

390.

2160

(6)

12–

40or

0.21

6–

40U

NS

2A0.

0009

0.21

510.

2100

0.19

890.

1960

0.00

2894

0.18

532B

0.18

90.

195

0.19

980.

2036

0.00

380.

2160

(6)

12–

48or

0.21

6–

48U

NS

2A0.

0008

0.21

520.

2107

0.20

170.

1990

0.00

2686

0.19

042B

0.19

30.

198

0.20

250.

2060

0.00

350.

2160

(6)

12–

56or

0.21

6–

56U

NS

2A0.

0008

0.21

520.

2111

0.20

360.

2011

0.00

2526

0.19

392B

0.19

70.

201

0.20

440.

2077

0.00

330.

2160

1 ⁄ 4–

24or

0.25

0–

24U

NS

2A0.

0011

0.24

890.

2417

0.22

180.

2181

0.00

3667

0.19

932B

0.20

50.

215

0.22

290.

2277

0.00

480.

2500

1 ⁄ 4–

27or

0.25

0–

27U

NS

2A0.

0010

0.24

900.

2423

0.22

490.

2214

0.00

3478

0.20

492B

0.21

00.

219

0.22

590.

2304

0.00

450.

2500

(6)

1 ⁄ 4–

36or

0.25

0–

36U

NS

2A0.

0009

0.24

910.

2436

0.23

110.

2280

0.00

3071

0.21

602B

0.22

00.

227

0.23

200.

2360

0.00

400.

2500

1 ⁄ 4–

40or

0.25

0–

40U

NS

2A0.

0009

0.24

910.

2440

0.23

290.

2300

0.00

2939

0.21

932B

0.22

30.

229

0.23

380.

2376

0.00

380.

2500

(6)

1 ⁄ 4–

48or

0.25

0–

48U

NS

2A0.

0008

0.24

920.

2447

0.23

570.

2330

0.00

2731

0.22

442B

0.22

70.

232

0.23

650.

2401

0.00

360.

2500

(6)

1 ⁄ 4–

56or

0.25

0–

56U

NS

2A0.

0008

0.24

920.

2451

0.23

760.

2350

0.00

2571

0.22

792B

0.23

10.

235

0.23

840.

2417

0.00

330.

2500

(6)

5 ⁄ 16–

27or

0.31

25–

27U

NS

2A0.

0011

0.31

140.

3047

0.28

730.

2837

0.00

3551

0.26

732B

0.27

20.

281

0.28

840.

2930

0.00

460.

3125

(6)

5 ⁄ 16–

36or

0.31

25–

36U

NS

2A0.

0009

0.31

160.

3061

0.29

360.

2905

0.00

3144

0.27

852B

0.28

20.

289

0.29

450.

2986

0.00

410.

3125

(6)

5 ⁄ 16–

40or

0.31

25–

40U

NS

2A0.

0009

0.31

160.

3065

0.29

540.

2924

0.00

3012

0.28

182B

0.28

50.

291

0.29

630.

3002

0.00

390.

3125

(6)

5 ⁄ 16–

48or

0.31

25–

48U

NS

2A0.

0008

0.31

170.

3072

0.29

820.

2954

0.00

2804

0.28

692B

0.29

00.

295

0.29

900.

3026

0.00

360.

3125

135



ASME B1.1-2003 NONMANDATORY APPENDIX D

Tabl

eD

-1Li

mit

sof

Size

for

Sele

cted

Com

bina

tion

sof

UN

S/U

NRS

Seri

esTh

read

s(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UN

RPi

tch

Dia

met

eran

dM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(3

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(3)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Max

.To

lera

nce

[Not

e(5

)]D

iam

eter

,Th

read

s/in

.na

tion

Clas

sA

llow

ance

[Not

e(2

)]M

in.

[Not

e(2

)]M

in.

[Not

e(4

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(6)

3 ⁄ 8–

18or

0.37

5–

18U

NS

2A0.

0013

0.37

370.

3650

0.33

760.

3333

0.00

4327

0.30

752B

0.31

50.

328

0.33

890.

3445

0.00

560.

3750

3 ⁄ 8–

27or

0.37

5–

27U

NS

2A0.

0011

0.37

390.

3672

0.34

980.

3462

0.00

3615

0.32

982B

0.33

50.

344

0.35

090.

3556

0.00

470.

3750

3 ⁄ 8–

36or

0.37

5–

36U

NS

2A0.

0010

0.37

400.

3685

0.35

600.

3528

0.00

3208

0.34

092B

0.34

50.

352

0.35

700.

3612

0.00

420.

3750

3 ⁄ 8–

40or

0.37

5–

40U

NS

2A0.

0009

0.37

410.

3690

0.35

790.

3548

0.00

3076

0.34

432B

0.34

80.

354

0.35

880.

3628

0.00

400.

3750

0.39

0–

27or

0.39

0–

27U

NS

2A0.

0011

0.38

890.

3822

0.36

480.

3612

0.00

3629

0.34

482B

0.35

00.

359

0.36

590.

3706

0.00

470.

3900

(6)

7 ⁄ 16–

18or

0.43

75–

18U

NS

2A0.

0013

0.43

620.

4275

0.40

010.

3957

0.00

4384

0.37

002B

0.37

70.

390

0.40

140.

4071

0.00

570.

4375

(6)

7 ⁄ 16–

24or

0.43

75–

24U

NS

2A0.

0012

0.43

630.

4291

0.40

920.

4053

0.00

3861

0.38

672B

0.39

20.

402

0.41

040.

4154

0.00

500.

4375

(6)

7 ⁄ 16–

27or

0.43

75–

27U

NS

2A0.

0011

0.43

640.

4297

0.41

230.

4086

0.00

3672

0.39

232B

0.39

70.

406

0.41

340.

4182

0.00

480.

4375

(6)

1 ⁄ 2–

12or

0.50

0–

12U

NS

2A0.

0016

0.49

840.

4870

0.44

430.

4389

0.00

5352

0.39

922B

0.41

00.

428

0.44

590.

4529

0.00

700.

5000

(6)

3A0.

0000

0.50

000.

4886

0.44

590.

4419

0.00

4000

0.40

083B

0.41

000.

4185

0.44

590.

4511

0.00

520.

5000

(6)

1 ⁄ 2–

14or

0.50

0–

14U

NS

2A0.

0015

0.49

850.

4882

0.45

210.

4471

0.00

4976

0.41

342B

0.42

30.

438

0.45

360.

4601

0.00

650.

5000

(6)

1 ⁄ 2–

18or

0.50

0–

18U

NS

2A0.

0013

0.49

870.

4900

0.46

260.

4582

0.00

4436

0.43

252B

0.44

00.

453

0.46

390.

4697

0.00

580.

5000

1 ⁄ 2–

24or

0.50

0–

24U

NS

2A0.

0012

0.49

880.

4916

0.47

170.

4678

0.00

3913

0.44

922B

0.45

50.

465

0.47

290.

4780

0.00

510.

5000

1 ⁄ 2–

27or

0.50

0–

27U

NS

2A0.

0011

0.49

890.

4922

0.47

480.

4711

0.00

3724

0.45

482B

0.46

00.

469

0.47

590.

4807

0.00

480.

5000

(6)

9 ⁄ 16

–14

or0.

5625

–14

UN

S2A

0.00

150.

5610

0.55

070.

5146

0.50

960.

0050

230.

4759

2B0.

485

0.50

10.

5161

0.52

260.

0065

0.56

25

(6)

9 ⁄ 16

–27

or0.

5625

–27

UN

S2A

0.00

110.

5614

0.55

470.

5373

0.53

350.

0037

710.

5173

2B0.

522

0.53

10.

5384

0.54

330.

0049

0.56

25

(6)

5 ⁄ 8–

14or

0.62

5–

14U

NS

2A0.

0015

0.62

350.

6132

0.57

710.

5720

0.00

5067

0.53

842B

0.54

80.

563

0.57

860.

5852

0.00

660.

6250

5 ⁄ 8–

27or

0.62

5–

27U

NS

2A0.

0011

0.62

390.

6172

0.59

980.

5960

0.00

3815

0.57

982B

0.58

50.

594

0.60

090.

6059

0.00

500.

6250

(6)

3 ⁄ 4–

14or

0.75

0–

14U

NS

2A0.

0015

0.74

850.

7382

0.70

210.

6970

0.00

5148

0.66

342B

0.67

30.

688

0.70

360.

7103

0.00

670.

7500

136


Tabl

eD

-1Li

mit

sof

Size

for

Sele

cted

Com

bina

tion

sof

UN

S/U

NRS

Seri

esTh

read

s(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UN

RPi

tch

Dia

met

eran

dM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(3

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(3)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Max

.To

lera

nce

[Not

e(5

)]D

iam

eter

,Th

read

s/in

.na

tion

Clas

sA

llow

ance

[Not

e(2

)]M

in.

[Not

e(2

)]M

in.

[Not

e(4

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(6)

3 ⁄ 4–

18or

0.75

0–

18U

NS

2A0.

0014

0.74

860.

7399

0.71

250.

7079

0.00

4608

0.68

242B

0.69

00.

703

0.71

390.

7199

0.00

600.

7500

3 ⁄ 4–

24or

0.75

0–

24U

NS

2A0.

0012

0.74

880.

7416

0.72

170.

7176

0.00

4085

0.69

922B

0.70

50.

715

0.72

290.

7282

0.00

530.

7500

3 ⁄ 4–

27or

0.75

0–

27U

NS

2A0.

0012

0.74

880.

7421

0.72

470.

7208

0.00

3896

0.70

472B

0.71

00.

719

0.72

590.

7310

0.00

510.

7500

(6)

7 ⁄ 8–

10or

0.87

5–

10U

NS

2A0.

0018

0.87

320.

8603

0.80

820.

8021

0.00

6090

0.75

412B

0.76

70.

788

0.81

000.

8179

0.00

790.

8750

(6)

7 ⁄ 8–

18or

0.87

5–

18U

NS

2A0.

0014

0.87

360.

8649

0.83

750.

8328

0.00

4680

0.80

742B

0.81

50.

828

0.83

890.

8450

0.00

610.

8750

(6)

7 ⁄ 8–

24or

0.87

5–

24U

NS

2A0.

0012

0.87

380.

8666

0.84

670.

8425

0.00

4157

0.82

422B

0.83

00.

840

0.84

790.

8533

0.00

540.

8750

(6)

7 ⁄ 8–

27or

0.87

5–

27U

NS

2A0.

0012

0.87

380.

8671

0.84

970.

8457

0.00

3968

0.82

972B

0.83

50.

844

0.85

090.

8561

0.00

520.

8750

(6)

1–

10or

1.00

0–

10U

NS

2A0.

0018

0.99

820.

9853

0.93

320.

9270

0.00

6155

0.87

912B

0.89

20.

913

0.93

500.

9430

0.00

801.

0000

(6)

1–

18or

1.00

0–

18U

NS

2A0.

0014

0.99

860.

9899

0.96

250.

9578

0.00

4745

0.93

242B

0.94

00.

953

0.96

390.

9701

0.00

621.

0000

1–

24or

1.00

0–

24U

NS

2A0.

0013

0.99

870.

9915

0.97

160.

9674

0.00

4222

0.94

912B

0.95

50.

965

0.97

290.

9784

0.00

551.

0000

1–

27or

1.00

0–

27U

NS

2A0.

0012

0.99

880.

9921

0.97

470.

9707

0.00

4033

0.95

472B

0.96

00.

969

0.97

590.

9811

0.00

521.

0000

(6)

11 ⁄ 8–

10or

1.12

5–

10U

NS

2A0.

0019

1.12

311.

1102

1.05

811.

0519

0.00

6215

1.00

402B

1.01

71.

038

1.06

001.

0681

0.00

811.

1250

(6)

11 ⁄ 8–

14or

1.12

5–

14U

NS

2A0.

0016

1.12

341.

1131

1.07

701.

0717

0.00

5345

1.03

832B

1.04

81.

063

1.07

861.

0855

0.00

691.

1250

(6)

11 ⁄ 8–

24or

1.12

5–

24U

NS

2A0.

0013

1.12

371.

1165

1.09

661.

0923

0.00

4282

1.07

412B

1.08

01.

090

1.09

791.

1035

0.00

561.

1250

(6)

11 ⁄ 4–

10or

1.25

0–

10U

NS

2A0.

0019

1.24

811.

2352

1.18

311.

1768

0.00

6271

1.12

902B

1.14

21.

163

1.18

501.

1932

0.00

821.

2500

(6)

11 ⁄ 4–

14or

1.25

0–

14U

NS

2A0.

0016

1.24

841.

2381

1.20

201.

1966

0.00

5401

1.16

332B

1.17

31.

188

1.20

361.

2106

0.00

701.

2500

11 ⁄ 4–

24or

1.25

0–

24U

NS

2A0.

0013

1.24

871.

2415

1.22

161.

2173

0.00

4338

1.19

912B

1.20

51.

215

1.22

291.

2285

0.00

561.

2500

(6)

13 ⁄ 8–

10or

1.37

5–

10U

NS

2A0.

0019

1.37

311.

3602

1.30

811.

3018

0.00

6323

1.25

402B

1.26

71.

288

1.31

001.

3182

0.00

821.

3750

(6)

13 ⁄ 8–

14or

1.37

5–

14U

NS

2A0.

0016

1.37

341.

3631

1.32

701.

3215

0.00

5453

1.28

832B

1.29

81.

313

1.32

861.

3357

0.00

711.

3750

137




Tabl

eD

-1Li

mit

sof

Size

for

Sele

cted

Com

bina

tion

sof

UN

S/U

NRS

Seri

esTh

read

s(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UN

RPi

tch

Dia

met

eran

dM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(3

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(3)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Max

.To

lera

nce

[Not

e(5

)]D

iam

eter

,Th

read

s/in

.na

tion

Clas

sA

llow

ance

[Not

e(2

)]M

in.

[Not

e(2

)]M

in.

[Not

e(4

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(6)

13 ⁄ 8–

24or

1.37

5–

24U

NS

2A0.

0013

1.37

371.

3665

1.34

661.

3422

0.00

4390

1.32

412B

1.33

01.

340

1.34

791.

3536

0.00

571.

3750

(6)

11 ⁄ 2–

10or

1.50

0–

10U

NS

2A0.

0019

1.49

811.

4852

1.43

311.

4267

0.00

6372

1.37

902B

1.39

21.

413

1.43

501.

4433

0.00

831.

5000

(6)

11 ⁄ 2–

14or

1.50

0–

14U

NS

2A0.

0017

1.49

831.

4880

1.45

191.

4464

0.00

5502

1.41

322B

1.42

31.

438

1.45

361.

4608

0.00

721.

5000

11 ⁄ 2–

24or

1.50

0–

24U

NS

2A0.

0013

1.49

871.

4915

1.47

161.

4672

0.00

4439

1.44

912B

1.45

51.

465

1.47

291.

4787

0.00

581.

5000

(6)

15 ⁄ 8–

10or

1.62

5–

10U

NS

2A0.

0019

1.62

311.

6102

1.55

811.

5517

0.00

6419

1.50

402B

1.51

71.

538

1.56

001.

5683

0.00

831.

6250

(6)

15 ⁄ 8–

14or

1.62

5–

14U

NS

2A0.

0017

1.62

331.

6130

1.57

691.

5714

0.00

5549

1.53

822B

1.54

81.

563

1.57

861.

5858

0.00

721.

6250

(6)

15 ⁄ 8–

24or

1.62

5–

24U

NS

2A0.

0013

1.62

371.

6165

1.59

661.

5921

0.00

4486

1.57

412B

1.58

01.

590

1.59

791.

6037

0.00

581.

6250

(6)

13 ⁄ 4–

10or

1.75

0–

10U

NS

2A0.

0019

1.74

811.

7352

1.68

311.

6766

0.00

6463

1.62

902B

1.64

21.

663

1.68

501.

6934

0.00

841.

7500

13 ⁄ 4–

14or

1.75

0–

14U

NS

2A0.

0017

1.74

831.

7380

1.70

191.

6963

0.00

5593

1.66

322B

1.67

31.

688

1.70

361.

7109

0.00

731.

7500

(6)

13 ⁄ 4–

18or

1.75

0–

18U

NS

2A0.

0015

1.74

851.

7398

1.71

241.

7073

0.00

5053

1.68

232B

1.69

01.

703

1.71

391.

7205

0.00

661.

7500

(6)

17 ⁄ 8–

10or

1.87

5–

10U

NS

2A0.

0020

1.87

301.

8601

1.80

801.

8015

0.00

6505

1.75

392B

1.76

71.

788

1.81

001.

8185

0.00

851.

8750

(6)

17 ⁄ 8–

14or

1.87

5–

14U

NS

2A0.

0017

1.87

331.

8630

1.82

691.

8213

0.00

5635

1.78

822B

1.79

81.

813

1.82

861.

8359

0.00

731.

8750

(6)

17 ⁄ 8–

18or

1.87

5–

18U

NS

2A0.

0015

1.87

351.

8648

1.83

741.

8323

0.00

5095

1.80

732B

1.81

51.

828

1.83

891.

8455

0.00

661.

8750

(6)

2–

10or

2.00

0–

10U

NS

2A0.

0020

1.99

801.

9851

1.93

301.

9265

0.00

6545

1.87

892B

1.89

21.

913

1.93

501.

9435

0.00

852.

0000

(6)

2–

14or

2.00

0–

14U

NS

2A0.

0017

1.99

831.

9880

1.95

191.

9462

0.00

5675

1.91

322B

1.92

31.

938

1.95

361.

9610

0.00

742.

0000

(6)

2–

18or

2.00

0–

18U

NS

2A0.

0015

1.99

851.

9898

1.96

241.

9573

0.00

5135

1.93

232B

1.94

01.

953

1.96

391.

9706

0.00

672.

0000

(6)

21 ⁄ 16

–16

or2.

063

–16

UN

S2A

0.00

162.

0609

2.05

152.

0203

2.01

490.

0053

961.

9865

2B1.

995

2.00

92.

0219

2.02

890.

0070

2.06

25(6

)3A

0.00

002.

0625

2.05

312.

0219

2.01

790.

0040

001.

9881

3B1.

9950

2.00

342.

0219

2.02

720.

0053

2.06

25

(6)

23 ⁄ 16

–16

or2.

1875

–16

UN

S2A

0.00

162.

1859

2.17

652.

1453

2.13

990.

0054

342.

1115

2B2.

120

2.13

42.

1469

2.15

400.

0071

2.18

75(6

)3A

0.00

002.

1875

2.17

812.

1469

2.14

280.

0041

002.

1131

3B2.

1200

2.12

842.

1469

2.15

220.

0053

2.18

75

138


Tabl

eD

-1Li

mit

sof

Size

for

Sele

cted

Com

bina

tion

sof

UN

S/U

NRS

Seri

esTh

read

s(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UN

RPi

tch

Dia

met

eran

dM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(3

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ncti

onal

Dia

met

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ax.

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orM

inor

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met

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ote

(3)]

Nom

inal

Siz

ean

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Max

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[Not

e(5

)]D

iam

eter

,Th

read

s/in

.na

tion

Clas

sA

llow

ance

[Not

e(2

)]M

in.

[Not

e(2

)]M

in.

[Not

e(4

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(6)

21 ⁄ 4–

10or

2.25

0–

10U

NS

2A00

202.

2480

2.23

512.

1830

2.17

640.

0066

212.

1289

2B2.

142

2.16

32.

1850

2.19

360.

0086

2.25

00

(6)

21 ⁄ 4–

14or

2.25

0–

14U

NS

2A0.

0017

2.24

832.

2380

2.20

192.

1961

0.00

5751

2.16

322B

2.17

32.

188

2.20

362.

2111

0.00

752.

2500

(6)

21 ⁄ 4–

18or

2.25

0–

18U

NS

2A0.

0016

2.24

842.

2397

2.21

232.

2071

0.00

5211

2.18

222B

2.19

02.

203

2.21

392.

2207

0.00

682.

2500

(6)

25 ⁄ 16

–16

or2.

3125

–16

UN

S2A

0.00

162.

3109

2.30

152.

2703

2.26

480.

0054

712.

2365

2B2.

245

2.25

92.

2719

2.27

900.

0071

2.31

25(6

)3A

0.00

002.

3125

2.30

312.

2719

2.26

780.

0041

002.

2381

3B2.

2450

2.25

342.

2719

2.27

720.

0053

2.31

25

(6)

27 ⁄ 16

–16

or2.

4375

–16

UN

S2A

0.00

172.

4358

2.42

642.

3952

2.38

970.

0055

062.

3614

2B2.

370

2.38

42.

3969

2.40

410.

0072

2.43

75(6

)3A

0.00

002.

4375

2.42

812.

3969

2.39

280.

0041

002.

3631

3B2.

3700

2.37

842.

3969

2.40

230.

0054

2.43

75

(6)

21 ⁄ 2–

10or

2.50

0–

10U

NS

2A0.

0020

2.49

802.

4851

2.43

302.

4263

0.00

6691

2.37

892B

2.39

22.

413

2.43

502.

4437

0.00

872.

5000

(6)

21 ⁄ 2–

14or

2.50

0–

14U

NS

2A0.

0017

2.49

832.

4880

2.45

192.

4461

0.00

5821

2.41

322B

2.42

32.

438

2.45

362.

4612

0.00

762.

5000

(6)

21 ⁄ 2–

18or

2.50

0–

18U

NS

2A0.

0016

2.49

842.

4897

2.46

232.

4570

0.00

5281

2.43

222B

2.44

02.

453

2.46

392.

4708

0.00

692.

5000

(6)

23 ⁄ 4–

10or

2.75

0–

10U

NS

2A0.

0020

2.74

802.

7351

2.68

302.

6762

0.00

6757

2.62

892B

2.64

22.

663

2.68

502.

6938

0.00

882.

7500

(6)

23 ⁄ 4–

14or

2.75

0–

14U

NS

2A0.

0018

2.74

822.

7379

2.70

182.

6959

0.00

5887

2.66

312B

2.67

32.

688

2.70

362.

7113

0.00

772.

7500

(6)

23 ⁄ 4–

18or

2.75

0–

18U

NS

2A0.

0016

2.74

842.

7397

2.71

232.

7070

0.00

5347

2.68

222B

2.69

02.

703

2.71

392.

7209

0.00

702.

7500

(6)

3–

10or

3.00

0–

10U

NS

2A0.

0020

2.99

802.

9851

2.93

302.

9262

0.00

6818

2.87

892B

2.89

22.

913

2.93

502.

9439

0.00

893.

0000

(6)

3–

14or

3.00

0–

14U

NS

2A0.

0018

2.99

822.

9879

2.95

182.

9459

0.00

5948

2.91

312B

2.92

32.

938

2.95

362.

9613

0.00

773.

0000

(6)

3–

18or

3.00

0–

18U

NS

2A0.

0016

2.99

842.

9897

2.96

232.

9569

0.00

5408

2.93

222B

2.94

02.

953

2.96

392.

9709

0.00

703.

0000

(6)

31 ⁄ 4–

10or

3.25

0–

10U

NS

2A0.

0021

3.24

793.

2350

3.18

293.

1760

0.00

6877

3.12

882B

3.14

23.

163

3.18

503.

1939

0.00

893.

2500

(6)

31 ⁄ 4–

14or

3.25

0–

14U

NS

2A0.

0018

3.24

823.

2379

3.20

183.

1958

0.00

6007

3.16

312B

3.17

33.

188

3.20

363.

2114

0.00

783.

2500

(6)

31 ⁄ 4–

18or

3.25

0–

18U

NS

2A0.

0016

3.24

843.

2397

3.21

233.

2068

0.00

5467

3.18

222B

3.19

03.

203

3.21

393.

2210

0.00

713.

2500

(6)

31 ⁄ 2–

10or

3.50

0–

10U

NS

2A0.

0021

3.49

793.

4850

3.43

293.

4260

0.00

6932

3.37

882B

3.39

23.

413

3.43

503.

4440

0.00

903.

5000

139




Tabl

eD

-1Li

mit

sof

Size

for

Sele

cted

Com

bina

tion

sof

UN

S/U

NRS

Seri

esTh

read

s(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UN

RPi

tch

Dia

met

eran

dM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(3

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(3)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Max

.To

lera

nce

[Not

e(5

)]D

iam

eter

,Th

read

s/in

.na

tion

Clas

sA

llow

ance

[Not

e(2

)]M

in.

[Not

e(2

)]M

in.

[Not

e(4

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(6)

31 ⁄ 2–

14or

3.50

0–

14U

NS

2A0.

0018

3.49

823.

4879

3.45

183.

4457

0.00

6062

3.41

312B

3.42

33.

438

3.45

363.

4615

0.00

793.

5000

(6)

31 ⁄ 2–

18or

3.50

0–

18U

NS

2A0.

0017

3.49

833.

4896

3.46

223.

4567

0.00

5522

3.43

212B

3.44

03.

453

3.46

393.

4711

0.00

723.

5000

(6)

33 ⁄ 4–

10or

3.75

0–

10U

NS

2A0.

0021

3.74

793.

7350

3.68

293.

6759

0.00

6985

3.62

882B

3.64

23.

663

3.68

503.

6941

0.00

913.

7500

(6)

33 ⁄ 4–

14or

3.75

0–

14U

NS

2A0.

0018

3.74

823.

7379

3.70

183.

6957

0.00

6115

3.66

312B

3.67

33.

688

3.70

363.

7115

0.00

793.

7500

(6)

33 ⁄ 4–

18or

3.75

0–

18U

NS

2A0.

0017

3.74

833.

7396

3.71

223.

7066

0.00

5575

3.68

212B

3.69

03.

703

3.71

393.

7211

0.00

723.

7500

(6)

4–

10or

4.00

0–

10U

NS

2A0.

0021

3.99

793.

9850

3.93

293.

9259

0.00

7036

3.87

882B

3.89

23.

913

3.93

503.

9441

0.00

914.

0000

(6)

4–

14or

4.00

0–

14U

NS

2A0.

0018

3.99

823.

9879

3.95

183.

9456

0.00

6166

3.91

312B

3.92

33.

938

3.95

363.

9616

0.00

804.

0000

(6)

41 ⁄ 4–

10or

4.25

0–

10U

NS

2A0.

0021

4.24

794.

2350

4.18

294.

1758

0.00

7085

4.12

882B

4.14

24.

163

4.18

504.

1942

0.00

924.

2500

(6)

41 ⁄ 4–

14or

4.25

0–

14U

NS

2A0.

0019

4.24

814.

2378

4.20

174.

1955

0.00

6215

4.16

302B

4.17

34.

188

4.20

364.

2117

0.00

814.

2500

(6)

41 ⁄ 2–

10or

4.50

0–

10U

NS

2A0.

0021

4.49

794.

4850

4.43

294.

4258

0.00

7131

4.37

882B

4.39

24.

413

4.43

504.

4443

0.00

934.

5000

(6)

41 ⁄ 2–

14or

4.50

0–

14U

NS

2A0.

0019

4.49

814.

4878

4.45

174.

4454

0.00

6261

4.41

302B

4.42

34.

438

4.45

364.

4617

0.00

814.

5000

(6)

43 ⁄ 4–

10or

4.75

0–

10U

NS

2A0.

0022

4.74

784.

7349

4.68

284.

6756

0.00

7176

4.62

872B

4.64

24.

663

4.68

504.

6943

0.00

934.

7500

(6)

43 ⁄ 4–

14or

4.75

0–

14U

NS

2A0.

0019

4.74

814.

7378

4.70

174.

6954

0.00

6306

4.66

302B

4.67

34.

688

4.70

364.

7118

0.00

824.

7500

(6)

5–

10or

5.00

0–

10U

NS

2A0.

0022

4.99

784.

9849

4.93

284.

9256

0.00

7220

4.87

872B

4.89

24.

913

4.93

504.

9444

0.00

945.

0000

(6)

5–

14or

5.00

0–

14U

NS

2A0.

0019

4.99

814.

9878

4.95

174.

9454

0.00

6350

4.91

302B

4.92

34.

938

4.95

364.

9619

0.00

835.

0000

(6)

51 ⁄ 4–

10or

5.25

0–

10U

NS

2A0.

0022

5.24

785.

2349

5.18

285.

1755

0.00

7262

5.12

872B

5.14

25.

163

5.18

505.

1944

0.00

945.

2500

(6)

51 ⁄ 4–

14or

5.25

0–

14U

NS

2A0.

0019

5.24

815.

2378

5.20

175.

1953

0.00

6392

5.16

302B

5.17

35.

188

5.20

365.

2119

0.00

835.

2500

(6)

51 ⁄ 2–

10or

5.50

0–

10U

NS

2A0.

0022

5.49

785.

4849

5.43

285.

4255

0.00

7303

5.37

872B

5.39

25.

413

5.43

505.

4445

0.00

955.

5000

140


Tabl

eD

-1Li

mit

sof

Size

for

Sele

cted

Com

bina

tion

sof

UN

S/U

NRS

Seri

esTh

read

s(C

ont’

d)

Exte

rnal

[Not

e(1

)]In

tern

al[N

ote

(1)]

UN

RPi

tch

Dia

met

eran

dM

inor

Func

tion

alD

iam

eter

Pitc

hD

iam

eter

and

Dia

met

er,

Maj

orD

iam

eter

[Not

e(3

)]Fu

ncti

onal

Dia

met

erS

erie

sM

ax.

Maj

orM

inor

Dia

met

er[N

ote

(3)]

Nom

inal

Siz

ean

dD

esig

-M

ax.

Max

.To

lera

nce

[Not

e(5

)]D

iam

eter

,Th

read

s/in

.na

tion

Clas

sA

llow

ance

[Not

e(2

)]M

in.

[Not

e(2

)]M

in.

[Not

e(4

)](R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

(6)

51 ⁄ 2–

14or

5.50

0–

14U

NS

2A0.

0019

5.49

815.

4878

5.45

175.

4453

0.00

6433

5.41

302B

5.42

35.

438

5.45

365.

4620

0.00

845.

5000

(6)

53 ⁄ 4–

10or

5.75

0–

10U

NS

2A0.

0022

5.74

785.

7349

5.68

285.

6755

0.00

7342

5.62

872B

5.64

25.

663

5.68

505.

6945

0.00

955.

7500

(6)

53 ⁄ 4–

14or

5.75

0–

14U

NS

2A0.

0019

5.74

815.

7378

5.70

175.

6952

0.00

6472

5.66

302B

5.67

35.

688

5.70

365.

7120

0.00

845.

7500

(6)

6–

10or

6.00

0–

10U

NS

2A0.

0022

5.99

785.

9849

5.93

285.

9254

0.00

7381

5.87

872B

5.89

25.

913

5.93

505.

9446

0.00

966.

0000

(6)

6–

14or

6.00

0–

14U

NS

2A0.

0020

5.99

805.

9877

5.95

165.

9451

0.00

6511

5.91

292B

5.92

35.

938

5.95

365.

9621

0.00

856.

0000

GEN

ERA

LN

OTE

S:

Ser

ies

desi

gnat

ion

show

nin

dica

tes

the

UN

thre

adfo

rm;

how

ever

,th

eU

NR

thre

adfo

rmm

aybe

spec

ified

bysu

bsti

tuti

ngU

NR

inpl

ace

ofU

Nin

all

desi

gnat

ions

for

exte

rnal

use

only

.

NO

TES

:(1

)Th

read

clas

ses

may

beco

mbi

ned.

See

para

.4.

2.(2

)Fo

rCl

ass

2Ath

read

sha

ving

anad

diti

vefin

ish,

the

max

imum

maj

oran

dpi

tch

diam

eter

s,af

ter

coat

ing,

may

equa

lth

eba

sic

size

s,w

hose

valu

esar

eth

esa

me

asth

eno

min

alm

ajor

diam

eter

and

the

min

imum

pitc

hdi

amet

ersh

own

for

Clas

s2B

,re

spec

tive

ly.

See

para

.4.

1.2.

(3)

See

para

.5.

2.1

for

Func

tion

alD

iam

eter

.(4

)2A

pitc

hdi

amet

erto

lera

nce

(Td 2

)is

liste

dan

dus

edto

asi

xpl

ace

deci

mal

toca

lcul

ate

the

liste

dCl

ass

1A/1

B,

2B,

3A/

3Bto

lera

nces

and

Clas

s1A

/2A

allo

wan

ces

and

all

dim

ensi

onal

limit

sw

hich

depe

ndup

onth

em.

(5)

UN

seri

esex

tern

alth

read

max

imum

min

ordi

amet

eris

basi

c(D

1in

para

.11

)fo

rCl

ass

3Aan

dba

sic

min

usal

low

ance

for

Clas

ses

1Aan

d2A

.(6

)O

neor

mor

eof

the

num

bers

liste

din

this

row

have

been

chan

ged

toco

rrec

tfo

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141




Table D-2 Major Diameter Tolerancesfor External Threads of Special

Diameters, Pitches, and Lengths ofEngagement (UNS/UNRS) — Classes

1A, 2A, and 3A

Major Diameter Tolerance

Class 2A andClass 1A Class 3AThreads/

in. 0.090 3�P2 0.060 3�P2

80 . . . 0.003272 . . . 0.003564 . . . 0.003856 . . . 0.0041

48 . . . 0.004544 . . . 0.004840 0.0077 0.005136 0.0083 0.0055

32 0.0089 0.006028 0.0098 0.006527 0.0100 0.006724 0.0108 0.0072

20 0.0122 0.008118 0.0131 0.008716 0.0142 0.009414 0.0155 0.0103

12 0.0172 0.011410 0.0194 0.0129

8 0.0225 0.01506 0.0273 0.01824 0.0357 0.0238

. . . . . . . . .

142


Table D-3 Allowances for External Threads of Special Diameters and Pitches(UNS/UNRS) — Classes 1A and 2A

Allowance based on basicmajor diameter of 0.0625 0.09375 0.125 0.1875 0.25 0.375 0.5 0.625 0.75 1 1.25 1.5

For diameter range above 0.0470 0.0781 0.1094 0.1562 0.2188 0.3125 0.4375 0.5625 0.6875 0.875 1.125 1.375

To and including 0.0781 0.1094 0.1562 0.2188 0.3125 0.4375 0.5625 0.6875 0.875 1.125 1.375 1.625

Threads/in. Major, Pitch, and Minor Diameter Allowances, in.

80 0.0006 0.0006 0.0006 0.0007 0.0007 . . . . . . . . . . . . . . . . . . . . .72 0.0006 0.0006 0.0006 0.0007 0.0007 0.0007 . . . . . . . . . . . . . . . . . .64 0.0006 0.0007 0.0007 0.0007 0.0007 0.0008 0.0008 . . . . . . . . . . . . . . .56 . . . 0.0007 0.0007 0.0007 0.0008 0.0008 0.0008 0.0009 0.0009 . . . . . . . . .48 . . . 0.0007 0.0008 0.0008 0.0008 0.0009 0.0009 0.0009 0.0009 . . . . . . . . .44 . . . 0.0008 0.0008 0.0008 0.0008 0.0009 0.0009 0.0009 0.0010 0.0010 . . . . . .40 . . . . . . 0.0008 0.0009 0.0009 0.0009 0.0010 0.0010 0.0010 0.0010 . . . . . .36 . . . . . . 0.0009 0.0009 0.0009 0.0010 0.0010 0.0010 0.0010 0.0011 0.0011 0.001232 . . . . . . 0.0009 0.0009 0.0010 0.0010 0.0010 0.0011 0.0011 0.0011 0.0012 0.001228 . . . . . . . . . 0.0010 0.0010 0.0011 0.0011 0.0011 0.0012 0.0012 0.0012 0.001327 . . . . . . . . . 0.0010 0.0010 0.0011 0.0011 0.0011 0.0012 0.0012 0.0012 0.001324 . . . . . . . . . 0.0011 0.0011 0.0011 0.0012 0.0012 0.0012 0.0013 0.0013 0.001320 . . . . . . . . . . . . 0.0012 0.0012 0.0013 0.0013 0.0013 0.0014 0.0014 0.001418 . . . . . . . . . . . . . . . 0.0013 0.0013 0.0014 0.0014 0.0014 0.0015 0.001516 . . . . . . . . . . . . . . . 0.0014 0.0014 0.0014 0.0015 0.0015 0.0015 0.001614 . . . . . . . . . . . . . . . . . . 0.0015 0.0015 0.0015 0.0016 0.0016 0.001712 . . . . . . . . . . . . . . . . . . 0.0016 0.0016 0.0017 0.0017 0.0017 0.001810 . . . . . . . . . . . . . . . . . . . . . . . . 0.0018 0.0018 0.0019 0.00198 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0021 0.0021 0.00216 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00244 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Allowance based on basicmajor diameter of 1.75 2 2.5 3 3.5 4 5 6 8 10 12

For diameter range above 1.625 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11

To and including 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11 13

Threads/in. Major, Pitch, and Minor Diameter Allowances, in.

80 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 0.0012 0.0013 0.0013 0.0013 . . . . . . . . . . . . . . . . . . . . .28 0.0013 0.0013 0.0014 0.0014 0.0014 0.0015 . . . . . . . . . . . . . . .27 0.0013 0.0013 0.0014 0.0014 0.0014 0.0015 0.0015 0.0016 . . . . . . . . .24 0.0014 0.0014 0.0014 0.0015 0.0015 0.0015 0.0016 0.0016 . . . . . . . . .20 0.0015 0.0015 0.0015 0.0016 0.0016 0.0016 0.0017 0.0017 . . . . . . . . .18 0.0015 0.0015 0.0016 0.0016 0.0017 0.0017 0.0017 0.0018 0.0019 . . . . . .16 0.0016 0.0016 0.0017 0.0017 0.0017 0.0018 0.0018 0.0019 0.0019 0.0020 . . .14 0.0017 0.0017 0.0017 0.0018 0.0018 0.0018 0.0019 0.0020 0.0020 0.0021 0.002212 0.0018 0.0018 0.0019 0.0019 0.0019 0.0020 0.0020 0.0021 0.0021 0.0022 0.002310 0.0019 0.0020 0.0020 0.0020 0.0021 0.0021 0.0022 0.0022 0.0023 0.0024 0.0024

8 0.0021 0.0022 0.0022 0.0023 0.0023 0.0023 0.0024 0.0024 0.0025 0.0026 0.00266 0.0025 0.0025 0.0025 0.0026 0.0026 0.0026 0.0027 0.0027 0.0028 0.0029 0.00294 . . . 0.0030 0.0031 0.0031 0.0031 0.0032 0.0032 0.0033 0.0034 0.0034 0.0035

GENERAL NOTE: Classes 1A and 2A allowances are determined by multiplying Class 2A pitch diameter tolerances (com-puted to six decimal places) by 0.3 and are based on lengths of engagement of nine pitches.

143




Table D-4 Pitch Diameter Tolerances for External Threads of Special Diameters, Pitches, andLengths of Engagement (UNS/UNRS) — Class 1A

Tolerance based on basic major diameter of 0.0625 0.09375 0.125 0.1875 0.25 0.375 0.5 0.625 0.75 1

For diameter range above 0.0470 0.0781 0.1094 0.1562 0.2188 0.3125 0.4375 0.5625 0.6875 0.875

To and including 0.0781 0.1094 0.1562 0.2188 0.3125 0.4375 0.5625 0.6875 0.875 1.125

Length of Engagement

Threads/in. Number of Pitches in. Pitch Diameter Tolerances, in.

� 5 to 15 0.06 to 0.19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80

16 to 30 0.191 to 0.38 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 0.07 to 0.21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

16 to 30 0.211 to 0.42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 0.08 to 0.23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

16 to 30 0.231 to 0.46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 0.09 to 0.27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

16 to 30 0.271 to 0.54 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 0.10 to 0.31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

16 to 30 0.311 to 0.62 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 0.11 to 0.34 . . . 0.0038 0.0039 0.0041 0.0042 0.0044 0.0046 0.0047 0.0049 0.005144

16 to 30 0.341 to 0.68 . . . 0.0048 0.0049 0.0051 0.0053 0.0056 0.0058 0.0059 0.0061 0.0063

� 5 to 15 0.12 to 0.38 . . . . . . 0.0041 0.0043 0.0044 0.0046 0.0048 0.0049 0.0050 0.005240

16 to 30 0.381 to 0.76 . . . . . . 0.0051 0.0053 0.0055 0.0058 0.0060 0.0061 0.0063 0.0066

� 5 to 15 0.14 to 0.42 . . . . . . 0.0043 0.0045 0.0046 0.0048 0.0050 0.0051 0.0052 0.005436

16 to 30 0.421 to 0.84 . . . . . . 0.0054 0.0056 0.0058 0.0060 0.0062 0.0064 0.0065 0.0068

� 5 to 15 0.16 to 0.47 . . . . . . 0.0045 0.0047 0.0048 0.0050 0.0052 0.0053 0.0055 0.005732

16 to 30 0.471 to 0.94 . . . . . . 0.0057 0.0059 0.0061 0.0063 0.0065 0.0067 0.0068 0.0071

� 5 to 15 0.18 to 0.54 . . . . . . . . . 0.0050 0.0051 0.0053 0.0055 0.0056 0.0058 0.006028

16 to 30 0.541 to 1.08 . . . . . . . . . 0.0063 0.0064 0.0067 0.0069 0.0070 0.0072 0.0075

� 5 to 15 0.19 to 0.56 . . . . . . . . . 0.0051 0.0052 0.0056 0.0056 0.0057 0.0058 0.006027

16 to 30 0.561 to 1.12 . . . . . . . . . 0.0064 0.0065 0.0068 0.0070 0.0072 0.0073 0.0076

� 5 to 15 0.21 to 0.62 . . . . . . . . . 0.0054 0.0055 0.0057 0.0059 0.0060 0.0061 0.006324

16 to 30 0.621 to 1.24 . . . . . . . . . 0.0067 0.0069 0.0071 0.0073 0.0075 0.0077 0.0079

� 5 to 15 0.25 to 0.75 . . . . . . . . . . . . 0.0060 0.0062 0.0063 0.0065 0.0066 0.006820

16 to 30 0.751 to 1.50 . . . . . . . . . . . . 0.0075 0.0077 0.0079 0.0081 0.0083 0.0085

� 5 to 15 0.28 to 0.83 . . . . . . . . . . . . . . . 0.0065 0.0067 0.0068 0.0069 0.007118

16 to 30 0.831 to 1.66 . . . . . . . . . . . . . . . 0.0081 0.0083 0.0085 0.0086 0.0089

� 5 to 15 0.31 to 0.94 . . . . . . . . . . . . . . . 0.0069 0.0070 0.0072 0.0073 0.007516

16 to 30 0.941 to 1.88 . . . . . . . . . . . . . . . 0.0086 0.0088 0.0089 0.0091 0.0094

� 5 to 15 0.36 to 1.07 . . . . . . . . . . . . . . . . . . 0.0075 0.0076 0.0077 0.007914

16 to 30 1.071 to 2.14 . . . . . . . . . . . . . . . . . . 0.0093 0.0095 0.0097 0.0099

� 5 to 15 0.42 to 1.25 . . . . . . . . . . . . . . . . . . 0.0080 0.0082 0.0083 0.008512

16 to 30 1.251 to 2.50 . . . . . . . . . . . . . . . . . . 0.0100 0.0102 0.0104 0.0106

� 5 to 15 0.50 to 1.50 . . . . . . . . . . . . . . . . . . . . . . . . 0.0090 0.009210

16 to 30 1.501 to 3.00 . . . . . . . . . . . . . . . . . . . . . . . . 0.0113 0.0115

� 5 to 15 0.62 to 1.88 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.01038

16 to 30 1.881 to 3.76 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0128

� 5 to 15 0.83 to 2.50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

16 to 30 2.501 to 5.00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 1.25 to 3.75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 16 to 30 3.751 to 7.50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GENERAL NOTES:(a) These values do not agree with and shall not be used in place of any tabulated values for the UNC, UNF, and 4-UN,

6-UN, and 8-UN thread series.

(b) Class 1A tolerances in this Table for 5 to 15 pitches are based on 9 pitches and are obtained by multiplying the Class2A (external thread) tolerances for 9 pitches taken to six decimal places (see Table 20) by a factor of 1.5.

(c) Class 1A tolerances in this Table for 16 to 30 pitches are obtained by multiplying the Class 2A (external thread) toler-ances for 9 pitches taken to six decimal places by a factor of 1.875 (obtained by multiplying the 1.5 factor by 1.25).For lengths of engagement not tabulated, see para. 5.

144



1.25 1.5 1.75 2 2.5 3 3.5 4 5 6 8 10 12

1.125 1.375 1.625 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11

1.375 1.625 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11 13

Pitch Diameter Tolerances, in. Threads/in.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 80

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 72

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 64

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 56

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 48

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 44

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 40

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.0056 0.0058 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 360.0070 0.0072 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.0058 0.0060 0.0061 0.0063 0.0065 0.0067 . . . . . . . . . . . . . . . . . . . . . � 320.0073 0.0075 0.0077 0.0078 0.0081 0.0083 . . . . . . . . . . . . . . . . . . . . .

0.0061 0.0063 0.0064 0.0066 0.0068 0.0070 0.0071 0.0073 . . . . . . . . . . . . . . . � 280.0077 0.0079 0.0080 0.0082 0.0085 0.0087 0.0089 0.0091 . . . . . . . . . . . . . . .

0.0061 0.0064 0.0065 0.0066 0.0069 0.0070 0.0072 0.0074 0.0076 0.0079 . . . . . . . . . � 270.0078 0.0080 0.0081 0.0083 0.0086 0.0088 0.0090 0.0092 0.0096 0.0099 . . . . . . . . .

0.0065 0.0067 0.0068 0.0069 0.0071 0.0073 0.0075 0.0077 0.0079 0.0082 . . . . . . . . . � 240.0081 0.0083 0.0085 0.0086 0.0089 0.0092 0.0094 0.0096 0.0099 0.0102 . . . . . . . . .

0.0070 0.0071 0.0073 0.0074 0.0076 0.0078 0.0080 0.0081 0.0084 0.0087 . . . . . . . . . � 200.0087 0.0089 0.0091 0.0092 0.0095 0.0098 0.0100 0.0102 0.0105 0.0108 . . . . . . . . .

0.0073 0.0074 0.0076 0.0077 0.0079 0.0081 0.0083 0.0084 0.0087 0.0090 0.0094 . . . . . . � 180.0091 0.0093 0.0095 0.0096 0.0099 0.0101 0.0104 0.0105 0.0109 0.0112 0.0117 . . . . . .

0.0077 0.0078 0.0078 0.0081 0.0083 0.0085 0.0086 0.0088 0.0091 0.0093 0.0097 0.0101 . . . � 160.0096 0.0098 0.0099 0.0101 0.0104 0.0106 0.0108 0.0110 0.0113 0.0116 0.0122 0.0126 . . .

0.0081 0.0083 0.0084 0.0085 0.0087 0.0089 0.0091 0.0092 0.0095 0.0098 0.0102 0.0105 0.0108 � 140.0101 0.0103 0.0105 0.0106 0.0109 0.0112 0.0114 0.0116 0.0119 0.0122 0.0127 0.0132 0.0135

0.0087 0.0088 0.0090 0.0091 0.0093 0.0095 0.0097 0.0098 0.0101 0.0103 0.0107 0.0111 0.0114 � 120.0108 0.0110 0.0112 0.0113 0.0116 0.0119 0.0121 0.0123 0.0126 0.0129 0.0134 0.0139 0.0142

0.0094 0.0096 0.0097 0.0098 0.0100 0.0102 0.0104 0.0106 0.0108 0.0111 0.0115 0.0118 0.0121 � 100.0118 0.0119 0.0121 0.0123 0.0125 0.0128 0.0130 0.0132 0.0135 0.0138 0.0144 0.0148 0.0152

0.0104 0.0106 0.0107 0.0108 0.0111 0.0113 0.0114 0.0116 0.0119 0.0121 0.0125 0.0129 0.0132 � 80.0130 0.0132 0.0134 0.0136 0.0138 0.0141 0.0143 0.0145 0.0148 0.0151 0.0156 0.0161 0.0165

. . . 0.0121 0.0123 0.0124 0.0126 0.0128 0.0130 0.0131 0.0134 0.0137 0.0141 0.0144 0.0147 � 6

. . . 0.0152 0.0154 0.0155 0.0158 0.0160 0.0162 0.0164 0.0168 0.0171 0.0176 0.0180 0.0184

. . . . . . . . . 0.0151 0.0154 0.0155 0.0157 0.0159 0.0162 0.0164 0.0168 0.0172 0.0175 � 4

. . . . . . . . . 0.0189 0.0192 0.0194 0.0196 0.0198 0.0202 0.0205 0.0210 0.0214 0.0214

(d) Pitches listed are those used most commonly and are recommended. Where intermediate pitches are specified, the for-mula in para. 5 should be applied.

(e) Tolerances are tabulated only for combinations of diameter, pitch, and length of engagement that are considered to begenerally used. For other combinations encountered, see para. 5.

145







To and including 0.0781 0.1094 0.1562 0.2188 0.3125 0.4375 0.5625 0.6875 0.875 1.125



� 5 to 15 0.06 to 0.19 0.0019 0.0020 0.0021 0.0022 0.0023 . . . . . . . . . . . . . . .80

16 to 30 0.191 to 0.38 0.0024 0.0025 0.0026 0.0027 0.0028 . . . . . . . . . . . . . . .

� 5 to 15 0.07 to 0.21 0.0020 0.0021 0.0021 0.0023 0.0023 0.0025 . . . . . . . . . . . .72

16 to 30 0.211 to 0.42 0.0025 0.0026 0.0027 0.0028 0.0029 0.0031 . . . . . . . . . . . .

� 5 to 15 0.08 to 0.23 0.0021 0.0022 0.0022 0.0024 0.0024 0.0026 0.0027 . . . . . . . . .64

16 to 30 0.231 to 0.46 0.0026 0.0027 0.0028 0.0029 0.0031 0.0032 0.0034 . . . . . . . . .

� 5 to 15 0.09 to 0.27 . . . 0.0023 0.0024 0.0025 0.0026 0.0027 0.0028 0.0029 0.0030 . . .56

16 to 30 0.271 to 0.54 . . . 0.0029 0.0030 0.0031 0.0032 0.0034 0.0035 0.0036 0.0037 . . .

� 5 to 15 0.10 to 0.31 . . . 0.0025 0.0025 0.0026 0.0027 0.0029 0.0030 0.0031 0.0031 . . .48

16 to 30 0.311 to 0.62 . . . 0.0031 0.0032 0.0033 0.0034 0.0036 0.0037 0.0038 0.0039 . . .

� 5 to 15 0.11 to 0.34 . . . 0.0026 0.0026 0.0027 0.0028 0.0030 0.0031 0.0032 0.0032 0.003444

16 to 30 0.341 to 0.68 . . . 0.0032 0.0033 0.0034 0.0035 0.0037 0.0038 0.0040 0.0041 0.0042

� 5 to 15 0.12 to 0.38 . . . . . . 0.0027 0.0029 0.0029 0.0031 0.0032 0.0033 0.0034 0.003540

16 to 30 0.381 to 0.76 . . . . . . 0.0034 0.0036 0.0037 0.0038 0.0040 0.0041 0.0042 0.0044

� 5 to 15 0.14 to 0.42 . . . . . . 0.0029 0.0030 0.0031 0.0032 0.0033 0.0034 0.0035 0.003636

16 to 30 0.421 to 0.84 . . . . . . 0.0036 0.0037 0.0038 0.0040 0.0041 0.0043 0.0044 0.0045

� 5 to 15 0.16 to 0.47 . . . . . . 0.0030 0.0031 0.0032 0.0034 0.0035 0.0036 0.0036 0.003832

16 to 30 0.471 to 0.94 . . . . . . 0.0038 0.0039 0.0040 0.0042 0.0043 0.0045 0.0046 0.0047

� 5 to 15 0.18 to 0.54 . . . . . . . . . 0.0033 0.0034 0.0036 0.0037 0.0038 0.0038 0.004028

16 to 30 0.541 to 1.08 . . . . . . . . . 0.0042 0.0043 0.0044 0.0046 0.0047 0.0048 0.0050

� 5 to 15 0.19 to 0.56 . . . . . . . . . 0.0034 0.0035 0.0036 0.0037 0.0038 0.0039 0.004027

16 to 30 0.561 to 1.12 . . . . . . . . . 0.0042 0.0043 0.0045 0.0047 0.0048 0.0049 0.0050

� 5 to 15 0.21 to 0.62 . . . . . . . . . 0.0036 0.0037 0.0038 0.0039 0.0040 0.0041 0.004224

16 to 30 0.621 to 1.24 . . . . . . . . . 0.0045 0.0046 0.0048 0.0049 0.0050 0.0051 0.0053

� 5 to 15 0.25 to 0.75 . . . . . . . . . . . . 0.0040 0.0041 0.0042 0.0043 0.0044 0.004520

16 to 30 0.751 to 1.50 . . . . . . . . . . . . 0.0050 0.0052 0.0053 0.0054 0.0055 0.0057

� 5 to 15 0.28 to 0.83 . . . . . . . . . . . . . . . 0.0043 0.0044 0.0045 0.0046 0.004718

16 to 30 0.831 to 1.66 . . . . . . . . . . . . . . . 0.0054 0.0055 0.0057 0.0058 0.0059

� 5 to 15 0.31 to 0.94 . . . . . . . . . . . . . . . 0.0046 0.0047 0.0048 0.0049 0.005016

16 to 30 0.941 to 1.88 . . . . . . . . . . . . . . . 0.0057 0.0058 0.0060 0.0061 0.0062

� 5 to 15 0.36 to 1.07 . . . . . . . . . . . . . . . . . . 0.0050 0.0051 0.0051 0.005314

16 to 30 1.071 to 2.14 . . . . . . . . . . . . . . . . . . 0.0062 0.0063 0.0064 0.0066

� 5 to 15 0.42 to 1.25 . . . . . . . . . . . . . . . . . . 0.0054 0.0054 0.0055 0.005712

16 to 30 1.251 to 2.50 . . . . . . . . . . . . . . . . . . 0.0067 0.0068 0.0069 0.0071

� 5 to 15 0.50 to 1.50 . . . . . . . . . . . . . . . . . . . . . . . . 0.0060 0.006210

16 to 30 1.501 to 3.00 . . . . . . . . . . . . . . . . . . . . . . . . 0.0075 0.0077

� 5 to 15 0.62 to 1.88 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00688

16 to 30 1.881 to 3.76 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0086

� 5 to 15 0.83 to 2.50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

16 to 30 2.501 to 5.00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 1.25 to 3.75 . . . . . . . . . . . . . . . . . . . . . . . . . . .4

16 to 30 3.751 to 7.50 . . . . . . . . . . . . . . . . . . . . . . . . . . .


6-UN, and 8-UN thread series.(b) Formula:

Class 2A tolerances p 0.0015 3�D + 0.0015 �LE + 0.015 3�P2, whereD p basic major diameterLE p length of engagementP p pitch

146



1.25 1.5 1.75 2 2.5 3 3.5 4 5 6 8 10 12

1.125 1.375 1.625 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11

1.375 1.625 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11 13


. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 80

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 72

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 64

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 56

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 48

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 44

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 40

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.0037 0.0038 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 360.0047 0.0048 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.0039 0.0040 0.0041 0.0042 0.0043 0.0044 . . . . . . . . . . . . . . . . . . . . . � 320.0049 0.0050 0.0051 0.0052 0.0054 0.0056 . . . . . . . . . . . . . . . . . . . . .

0.0041 0.0042 0.0043 0.0044 0.0045 0.0046 0.0048 0.0049 . . . . . . . . . . . . . . . � 280.0051 0.0052 0.0054 0.0055 0.0056 0.0058 0.0059 0.0061 . . . . . . . . . . . . . . .

0.0041 0.0042 0.0043 0.0044 0.0046 0.0047 0.0048 0.0049 0.0051 0.0053 . . . . . . . . . � 270.0052 0.0053 0.0054 0.0055 0.0057 0.0059 0.0060 0.0061 0.0064 0.0066 . . . . . . . . .

0.0043 0.0044 0.0045 0.0046 0.0048 0.0049 0.0050 0.0051 0.0053 0.0054 . . . . . . . . . � 240.0054 0.0055 0.0057 0.0058 0.0059 0.0061 0.0062 0.0064 0.0066 0.0068 . . . . . . . . .

0.0047 0.0048 0.0048 0.0049 0.0051 0.0052 0.0053 0.0054 0.0056 0.0058 . . . . . . . . . � 200.0058 0.0059 0.0061 0.0062 0.0063 0.0065 0.0066 0.0068 0.0070 0.0072 . . . . . . . . .

0.0049 0.0050 0.0051 0.0051 0.0053 0.0054 0.0055 0.0056 0.0058 0.0060 0.0062 . . . . . . � 180.0061 0.0062 0.0063 0.0064 0.0066 0.0068 0.0069 0.0070 0.0073 0.0075 0.0078 . . . . . .

0.0051 0.0052 0.0053 0.0054 0.0055 0.0056 0.0058 0.0059 0.0061 0.0062 0.0065 0.0067 . . . � 160.0064 0.0065 0.0066 0.0067 0.0069 0.0071 0.0072 0.0073 0.0076 0.0078 0.0081 0.0084 . . .

0.0054 0.0055 0.0056 0.0057 0.0058 0.0059 0.0061 0.0062 0.0064 0.0065 0.0068 0.0070 0.0072 � 140.0068 0.0069 0.0070 0.0071 0.0073 0.0074 0.0076 0.0077 0.0079 0.0081 0.0085 0.0088 0.0090

0.0058 0.0059 0.0060 0.0061 0.0062 0.0063 0.0064 0.0065 0.0067 0.0069 0.0072 0.0074 0.0076 � 120.0072 0.0073 0.0075 0.0076 0.0077 0.0079 0.0080 0.0082 0.0084 0.0086 0.0090 0.0092 0.0095

0.0063 0.0064 0.0065 0.0065 0.0067 0.0068 0.0069 0.0070 0.0072 0.0074 0.0077 0.0079 0.0081 � 100.0078 0.0080 0.0081 0.0082 0.0084 0.0085 0.0087 0.0088 0.0090 0.0092 0.0096 0.0099 0.0101

0.0070 0.0071 0.0071 0.0072 0.0074 0.0075 0.0076 0.0077 0.0079 0.0081 0.0083 0.0086 0.0088 � 80.0087 0.0088 0.0089 0.0090 0.0092 0.0094 0.0095 0.0097 0.0099 0.0101 0.0104 0.0107 0.0110

. . . 0.0081 0.0082 0.0083 0.0084 0.0085 0.0087 0.0088 0.0089 0.0091 0.0094 0.0096 0.0098 � 6

. . . 0.0101 0.0102 0.0103 0.0105 0.0107 0.0108 0.0110 0.0112 0.0114 0.0117 0.0120 0.0123

. . . . . . . . . 0.0101 0.0102 0.0104 0.0105 0.0106 0.0108 0.0109 0.0112 0.0114 0.0116 � 4

. . . . . . . . . 0.0126 0.0128 0.0130 0.0131 0.0132 0.0135 0.0137 0.0140 0.0143 0.0145

(c) Length of engagement increments included in the tabulated tolerances for length of engagement of from 5 to 15pitches are based on lengths of 9 pitches; those for lengths of engagement of from 16 to 30 pitches are obtained bymultiplying the 9 pitch values taken to six decimal places by 1.25. For lengths of engagement not tabulated, the for-mula in (b) above should be applied except as modified.

(d) Pitches listed are those used most commonly and are recommended. When intermediate pitches are specified, the for-mula in (b) above should be applied.


147







To and including 0.0781 0.1094 0.1562 0.2188 0.3125 0.4375 0.5625 0.6875 0.875 1.125



� 5 to 15 0.06 to 0.19 0.0014 0.0015 0.0015 0.0016 0.0017 . . . . . . . . . . . . . . .80

16 to 30 0.191 to 0.38 0.0018 0.0019 0.0019 0.0020 0.0021 . . . . . . . . . . . . . . .

� 5 to 15 0.07 to 0.21 0.0015 0.0016 0.0016 0.0017 0.0018 0.0019 . . . . . . . . . . . .72

16 to 30 0.211 to 0.42 0.0019 0.0019 0.0020 0.0021 0.0022 0.0023 . . . . . . . . . . . .

� 5 to 15 0.08 to 0.23 0.0016 0.0016 0.0017 0.0018 0.0018 0.0019 0.0020 . . . . . . . . .64

16 to 30 0.231 to 0.46 0.0020 0.0020 0.0021 0.0022 0.0023 0.0024 0.0025 . . . . . . . . .

� 5 to 15 0.09 to 0.27 . . . 0.0017 0.0018 0.0019 0.0019 0.0020 0.0021 0.0022 0.0022 . . .56

16 to 30 0.271 to 0.54 . . . 0.0022 0.0022 0.0023 0.0024 0.0025 0.0026 0.0027 0.0028 . . .

� 5 to 15 0.10 to 0.31 . . . 0.0019 0.0019 0.0019 0.0020 0.0020 0.0022 0.0023 0.0024 . . .48

16 to 30 0.311 to 0.62 . . . 0.0022 0.0023 0.0024 0.0025 0.0026 0.0027 0.0029 0.0030 . . .

� 5 to 15 0.11 to 0.34 . . . 0.0019 0.0020 0.0021 0.0021 0.0022 0.0023 0.0024 0.0024 0.002544

16 to 30 0.341 to 0.68 . . . 0.0024 0.0025 0.0026 0.0026 0.0028 0.0029 0.0030 0.0030 0.0032

� 5 to 15 0.12 to 0.38 . . . . . . 0.0021 0.0021 0.0022 0.0023 0.0024 0.0025 0.0025 0.002640

16 to 30 0.381 to 0.76 . . . . . . 0.0026 0.0027 0.0028 0.0029 0.0030 0.0031 0.0031 0.0033

� 5 to 15 0.14 to 0.42 . . . . . . 0.0022 0.0022 0.0023 0.0024 0.0025 0.0026 0.0026 0.002736

16 to 30 0.421 to 0.84 . . . . . . 0.0027 0.0028 0.0029 0.0030 0.0031 0.0032 0.0033 0.0034

� 5 to 15 0.16 to 0.47 . . . . . . 0.0023 0.0024 0.0024 0.0025 0.0026 0.0027 0.0027 0.002832

16 to 30 0.471 to 0.94 . . . . . . 0.0028 0.0029 0.0030 0.0032 0.0033 0.0033 0.0034 0.0035

� 5 to 15 0.18 to 0.54 . . . . . . . . . 0.0025 0.0026 0.0027 0.0028 0.0028 0.0029 0.003028

16 to 30 0.541 to 1.08 . . . . . . . . . 0.0031 0.0032 0.0033 0.0034 0.0035 0.0036 0.0037

� 5 to 15 0.19 to 0.56 . . . . . . . . . 0.0025 0.0026 0.0027 0.0028 0.0029 0.0029 0.003027

16 to 30 0.561 to 1.12 . . . . . . . . . 0.0032 0.0033 0.0034 0.0035 0.0036 0.0037 0.0038

� 5 to 15 0.21 to 0.62 . . . . . . . . . 0.0027 0.0028 0.0029 0.0029 0.0030 0.0031 0.003224

16 to 30 0.621 to 1.24 . . . . . . . . . 0.0034 0.0034 0.0036 0.0037 0.0038 0.0038 0.0040

� 5 to 15 0.25 to 0.75 . . . . . . . . . . . . 0.0030 0.0031 0.0032 0.0032 0.0033 0.003420

16 to 30 0.751 to 1.50 . . . . . . . . . . . . 0.0037 0.0039 0.0040 0.0041 0.0041 0.0043

� 5 to 15 0.28 to 0.83 . . . . . . . . . . . . . . . 0.0032 0.0033 0.0034 0.0035 0.003618

16 to 30 0.831 to 1.66 . . . . . . . . . . . . . . . 0.0041 0.0042 0.0042 0.0043 0.0044

� 5 to 15 0.31 to 0.94 . . . . . . . . . . . . . . . 0.0034 0.0035 0.0036 0.0036 0.003716

16 to 30 0.941 to 1.88 . . . . . . . . . . . . . . . 0.0043 0.0044 0.0045 0.0045 0.0047

� 5 to 15 0.36 to 1.07 . . . . . . . . . . . . . . . . . . 0.0037 0.0038 0.0039 0.004014

16 to 30 1.071 to 2.14 . . . . . . . . . . . . . . . . . . 0.0047 0.0048 0.0048 0.0050

� 5 to 15 0.42 to 1.25 . . . . . . . . . . . . . . . . . . 0.0040 0.0041 0.0041 0.004212

16 to 30 1.251 to 2.50 . . . . . . . . . . . . . . . . . . 0.0050 0.0051 0.0052 0.0053

� 5 to 15 0.50 to 1.50 . . . . . . . . . . . . . . . . . . . . . . . . 0.0045 0.004610

16 to 30 1.501 to 3.00 . . . . . . . . . . . . . . . . . . . . . . . . 0.0056 0.0058

� 5 to 15 0.62 to 1.88 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00518

16 to 30 1.881 to 3.76 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0064

� 5 to 15 0.83 to 2.50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

16 to 30 2.501 to 5.00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 1.25 to 3.75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

16 to 30 3.751 to 7.50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


6-UN, and 8-UN thread series.(b) Class 3A tolerances in this Table for 5 to 15 pitches are based on 9 pitches and are obtained by multiplying the Class

2A (external thread) tolerances for 9 pitches taken to six decimal places by a factor 0f 0.75.(c) Class 3A tolerances in this Table for 16 to 30 pitches are obtained by multiplying the Class 2A (external thread) toler-

ances for 9 pitches taken to six decimal places by a factor of 0.9375 (obtained by multiplying the 0.75 factor by 1.25).For lengths of engagement not tabulated, see para. 5.

148



1.25 1.5 1.75 2 2.5 3 3.5 4 5 6 8 10 12

1.125 1.375 1.625 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11

1.375 1.625 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11 13


. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 80

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 72

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 64

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 56

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 48

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 44

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 40

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.0028 0.0029 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 360.0035 0.0036 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.0029 0.0030 0.0031 0.0031 0.0032 0.0033 . . . . . . . . . . . . . . . . . . . . . � 320.0037 0.0038 0.0038 0.0039 0.0040 0.0042 . . . . . . . . . . . . . . . . . . . . .

0.0031 0.0031 0.0032 0.0033 0.0034 0.0035 0.0036 0.0036 . . . . . . . . . . . . . . . � 280.0038 0.0039 0.0040 0.0041 0.0042 0.0044 0.0045 0.0046 . . . . . . . . . . . . . . .

0.0031 0.0032 0.0033 0.0033 0.0034 0.0035 0.0036 0.0037 0.0038 0.0039 . . . . . . . . . � 270.0039 0.0040 0.0041 0.0041 0.0043 0.0044 0.0045 0.0046 0.0048 0.0049 . . . . . . . . .

0.0033 0.0033 0.0034 0.0035 0.0036 0.0037 0.0037 0.0038 0.0040 0.0041 . . . . . . . . . � 240.0041 0.0042 0.0042 0.0043 0.0045 0.0046 0.0047 0.0048 0.0050 0.0051 . . . . . . . . .

0.0035 0.0036 0.0036 0.0037 0.0038 0.0039 0.0040 0.0041 0.0042 0.0043 . . . . . . . . . � 200.0044 0.0045 0.0045 0.0046 0.0048 0.0049 0.0050 0.0051 0.0053 0.0054 . . . . . . . . .

0.0036 0.0037 0.0038 0.0039 0.0040 0.0041 0.0041 0.0042 0.0044 0.0045 0.0047 . . . . . . � 180.0046 0.0047 0.0047 0.0048 0.0050 0.0051 0.0052 0.0053 0.0054 0.0056 0.0059 . . . . . .

0.0038 0.0039 0.0040 0.0040 0.0041 0.0042 0.0043 0.0045 0.0045 0.0047 0.0049 0.0050 . . . � 160.0048 0.0049 0.0050 0.0050 0.0052 0.0053 0.0054 0.0055 0.0057 0.0058 0.0061 0.0063 . . .

0.0041 0.0041 0.0042 0.0043 0.0044 0.0045 0.0045 0.0046 0.0048 0.0049 0.0051 0.0053 0.0054 � 140.0051 0.0052 0.0052 0.0053 0.0055 0.0056 0.0057 0.0058 0.0060 0.0061 0.0064 0.0066 0.0068

0.0043 0.0044 0.0045 0.0045 0.0046 0.0047 0.0048 0.0049 0.0050 0.0052 0.0054 0.0055 0.0057 � 120.0054 0.0055 0.0056 0.0057 0.0058 0.0059 0.0060 0.0061 0.0063 0.0065 0.0067 0.0069 0.0071

0.0047 0.0048 0.0048 0.0049 0.0050 0.0051 0.0052 0.0053 0.0054 0.0055 0.0057 0.0059 0.0061 � 100.0059 0.0060 0.0061 0.0061 0.0063 0.0064 0.0065 0.0066 0.0068 0.0069 0.0072 0.0074 0.0076

0.0052 0.0053 0.0054 0.0054 0.0055 0.0056 0.0057 0.0058 0.0059 0.0061 0.0063 0.0064 0.0066 � 80.0065 0.0066 0.0067 0.0068 0.0069 0.0070 0.0071 0.0072 0.0074 0.0076 0.0078 0.0080 0.0082

. . . 0.0061 0.0061 0.0062 0.0063 0.0064 0.0065 0.0066 0.0067 0.0068 0.0070 0.0072 0.0074 � 6

. . . 0.0076 0.0077 0.0078 0.0079 0.0080 0.0081 0.0082 0.0084 0.0085 0.0088 0.0090 0.0092

. . . . . . . . . 0.0076 0.0077 0.0078 0.0079 0.0079 0.0081 0.0082 0.0084 0.0086 0.0087 � 4

. . . . . . . . . 0.0095 0.0096 0.0097 0.0098 0.0099 0.0101 0.0102 0.0105 0.0107 0.0109



149




Table D-7 Pitch Diameter Tolerances for Internal Threads of Special Diameters, Pitches, andLengths of Engagement (UNS/UNRS) — Class 1B



To and including 0.0781 0.1094 0.1562 0.2188 0.3125 0.4375 0.5625 0.6875 0.875 1.125



� 5 to 15 0.06 to 0.19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80

16 to 30 0.191 to 0.38 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 0.07 to 0.21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

16 to 30 0.211 to 0.42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 0.08 to 0.23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

16 to 30 0.231 to 0.46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 0.09 to 0.27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

16 to 30 0.271 to 0.54 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 0.10 to 0.31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

16 to 30 0.311 to 0.62 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 0.11 to 0.34 . . . 0.0050 0.0051 0.0053 0.0055 0.0058 0.0060 0.0062 0.0063 0.006644

16 to 30 0.341 to 0.68 . . . 0.0062 0.0064 0.0067 0.0069 0.0072 0.0075 0.0077 0.0079 0.0082

� 5 to 15 0.12 to 0.38 . . . . . . 0.0054 0.0056 0.0057 0.0060 0.0062 0.0064 0.0065 0.006840

16 to 30 0.381 to 0.76 . . . . . . 0.0067 0.0070 0.0072 0.0075 0.0078 0.0080 0.0082 0.0085

� 5 to 15 0.14 to 0.42 . . . . . . 0.0056 0.0058 0.0060 0.0063 0.0065 0.0066 0.0068 0.007136

16 to 30 0.421 to 0.84 . . . . . . 0.0070 0.0073 0.0075 0.0078 0.0081 0.0083 0.0085 0.0088

� 5 to 15 0.16 to 0.47 . . . . . . 0.0059 0.0061 0.0063 0.0066 0.0068 0.0070 0.0071 0.007432

16 to 30 0.471 to 0.94 . . . . . . 0.0074 0.0077 0.0079 0.0082 0.0085 0.0087 0.0089 0.0092

� 5 to 15 0.18 to 0.54 . . . . . . . . . 0.0065 0.0067 0.0069 0.0072 0.0073 0.0075 0.007828

16 to 30 0.541 to 1.08 . . . . . . . . . 0.0081 0.0083 0.0087 0.0089 0.0092 0.0094 0.0097

� 5 to 15 0.19 to 0.56 . . . . . . . . . 0.0066 0.0068 0.0070 0.0073 0.0074 0.0076 0.007927

16 to 30 0.561 to 1.12 . . . . . . . . . 0.0083 0.0085 0.0088 0.0091 0.0093 0.0095 0.0098

� 5 to 15 0.21 to 0.62 . . . . . . . . . 0.0070 0.0072 0.0074 0.0076 0.0078 0.0080 0.008224

16 to 30 0.621 to 1.24 . . . . . . . . . 0.0087 0.0089 0.0093 0.0095 0.0098 0.0100 0.0103

� 5 to 15 0.25 to 0.75 . . . . . . . . . . . . 0.0078 0.0080 0.0083 0.0084 0.0086 0.008920

16 to 30 0.751 to 1.50 . . . . . . . . . . . . 0.0097 0.0101 0.0103 0.0105 0.0107 0.0111

� 5 to 15 0.28 to 0.83 . . . . . . . . . . . . . . . 0.0084 0.0087 0.0088 0.0090 0.009318

16 to 30 0.831 to 1.66 . . . . . . . . . . . . . . . 0.0105 0.0108 0.0110 0.0112 0.0116

� 5 to 15 0.31 to 0.94 . . . . . . . . . . . . . . . 0.0089 0.0091 0.0093 0.0095 0.009716

16 to 30 0.941 to 1.88 . . . . . . . . . . . . . . . 0.0111 0.0114 0.0116 0.0118 0.0122

� 5 to 15 0.36 to 1.07 . . . . . . . . . . . . . . . . . . 0.0097 0.0099 0.0100 0.010314

16 to 30 1.071 to 2.14 . . . . . . . . . . . . . . . . . . 0.0121 0.0124 0.0125 0.0129

� 5 to 15 0.42 to 1.25 . . . . . . . . . . . . . . . . . . 0.0104 0.0106 0.0108 0.010912

16 to 30 1.251 to 2.50 . . . . . . . . . . . . . . . . . . 0.0130 0.0133 0.0135 0.0138

� 5 to 15 0.50 to 1.50 . . . . . . . . . . . . . . . . . . . . . . . . 0.0117 0.012010

16 to 30 1.501 to 3.00 . . . . . . . . . . . . . . . . . . . . . . . . 0.0147 0.0150

� 5 to 15 0.62 to 1.88 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.01338

16 to 30 1.881 to 3.76 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0167

� 5 to 15 0.83 to 2.50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

16 to 30 2.501 to 5.00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 1.25 to 3.75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

16 to 30 3.751 to 7.50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


6-UN, and 8-UN thread series.(b) Class 1B (internal thread) tolerances in this Table for 5 to 15 pitches are based on 9 pitches and are obtained by multi-

plying the Class 2A (external thread) tolerances for 9 pitches taken to six decimal places by a factor of 1.95.(c) Class 1B tolerances in this Table for 16 to 30 pitches are obtained by multiplying the Class 2A (external thread) toler-


150


Table D-7 Pitch Diameter Tolerances for External Threads of Special Diameters, Pitches, andLengths of Engagement (UNS/UNRS) — Class 1B

1.25 1.5 1.75 2 2.5 3 3.5 4 5 6 8 10 12

1.125 1.375 1.625 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11

1.375 1.625 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11 13


. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 80

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 72

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 64

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 56

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 48

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 44

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 40

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.0073 0.0075 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 360.0091 0.0094 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.0076 0.0078 0.0080 0.0081 0.0084 0.0087 . . . . . . . . . . . . . . . . . . . . . � 320.0095 0.0098 0.0100 0.0102 0.0105 0.0108 . . . . . . . . . . . . . . . . . . . . .

0.0080 0.0082 0.0084 0.0085 0.0088 0.0090 0.0093 0.0095 . . . . . . . . . . . . . . . � 280.0100 0.0102 0.0104 0.0106 0.0110 0.0113 0.0116 0.0118 . . . . . . . . . . . . . . .

0.0080 0.0083 0.0085 0.0085 0.0089 0.0092 0.0094 0.0096 0.0099 0.0103 . . . . . . . . . � 270.0101 0.0104 0.0106 0.0108 0.0111 0.0114 0.0117 0.0120 0.0124 0.0128 . . . . . . . . .

0.0085 0.0087 0.0088 0.0090 0.0093 0.0095 0.0097 0.0100 0.0103 0.0106 . . . . . . . . . � 240.0106 0.0106 0.0110 0.0112 0.0116 0.0119 0.0122 0.0124 0.0129 0.0133 . . . . . . . . .

0.0091 0.0093 0.0095 0.0096 0.0099 0.0101 0.0104 0.0106 0.0109 0.0112 . . . . . . . . . � 200.0114 0.0116 0.0118 0.0120 0.0124 0.0127 0.0130 0.0132 0.0137 0.0141 . . . . . . . . .

0.0095 0.0097 0.0099 0.0100 0.0103 0.0105 0.0108 0.0110 0.0113 0.0116 0.0122 . . . . . . � 180.0118 0.0121 0.0123 0.0125 0.0129 0.0132 0.0135 0.0137 0.0142 0.0146 0.0152 . . . . . .

0.0100 0.0101 0.0103 0.0105 0.0108 0.0110 0.0112 0.0114 0.0118 0.0121 0.0126 0.0131 . . . � 160.0124 0.0127 0.0129 0.0131 0.0135 0.0138 0.0140 0.0143 0.0148 0.0151 0.0158 0.0164 . . .

0.0105 0.0107 0.0109 0.0111 0.0114 0.0116 0.0118 0.0120 0.0124 0.0127 0.0132 0.0137 0.0141 � 140.0132 0.0134 0.0136 0.0138 0.0142 0.0145 0.0148 0.0150 0.0155 0.0159 0.0165 0.0171 0.0176

0.0113 0.0115 0.0116 0.0118 0.0121 0.0123 0.0126 0.0128 0.0131 0.0134 0.0140 0.0144 0.0148 � 120.0141 0.0143 0.0145 0.0147 0.0151 0.0154 0.0157 0.0159 0.0164 0.0168 0.0175 0.0180 0.0185

0.0122 0.0124 0.0126 0.0128 0.0130 0.0133 0.0135 0.0137 0.0141 0.0144 0.0149 0.0154 0.0158 � 100.0153 0.0155 0.0158 0.0160 0.0163 0.0166 0.0169 0.0172 0.0176 0.0180 0.0187 0.0192 0.0197

0.0136 0.0138 0.0139 0.0141 0.0144 0.0146 0.0149 0.0151 0.0154 0.0157 0.0163 0.0167 0.0171 � 80.0170 0.0172 0.0174 0.0176 0.0180 0.0183 0.0186 0.0188 0.0193 0.0197 0.0203 0.0209 0.0214

. . . 0.0158 0.0160 0.0161 0.0164 0.0167 0.0169 0.0171 0.0174 0.0178 0.0183 0.0187 0.0191 � 6

. . . 0.0197 0.0200 0.0202 0.0205 0.0208 0.0211 0.0214 0.0218 0.0222 0.0229 0.0234 0.0239

. . . . . . . . . 0.0197 0.0200 0.0202 0.0204 0.0206 0.0210 0.0213 0.0218 0.0223 0.0227 � 4

. . . . . . . . . 0.0246 0.0250 0.0253 0.0255 0.0258 0.0262 0.0266 0.0273 0.0279 0.0284



151







To and including 0.0781 0.1094 0.1562 0.2188 0.3125 0.4375 0.5625 0.6875 0.875 1.125



� 5 to 15 0.06 to 0.19 0.0025 0.0026 0.0027 0.0028 0.0029 . . . . . . . . . . . . . . .80

16 to 30 0.191 to 0.38 0.0031 0.0032 0.0033 0.0035 0.0037 . . . . . . . . . . . . . . .

� 5 to 15 0.07 to 0.21 0.0026 0.0027 0.0028 0.0029 0.0030 0.0032 . . . . . . . . . . . .72

16 to 30 0.211 to 0.42 0.0032 0.0034 0.0035 0.0037 0.0038 0.0040 . . . . . . . . . . . .

� 5 to 15 0.08 to 0.23 0.0027 0.0028 0.0029 0.0031 0.0032 0.0034 0.0035 . . . . . . . . .64

16 to 30 0.231 to 0.46 0.0034 0.0035 0.0037 0.0038 0.0040 0.0042 0.0044 . . . . . . . . .

� 5 to 15 0.09 to 0.27 . . . 0.0030 0.0031 0.0032 0.0033 0.0035 0.0037 0.0038 0.0039 . . .56

16 to 30 0.271 to 0.54 . . . 0.0037 0.0039 0.0040 0.0042 0.0044 0.0046 0.0047 0.0049 . . .

� 5 to 15 0.10 to 0.31 . . . 0.0032 0.0033 0.0034 0.0036 0.0037 0.0039 0.0040 0.0041 . . .48

16 to 30 0.311 to 0.62 . . . 0.0040 0.0041 0.0043 0.0044 0.0047 0.0048 0.0050 0.0051 . . .

� 5 to 15 0.11 to 0.34 . . . 0.0033 0.0034 0.0036 0.0037 0.0039 0.0040 0.0041 0.0042 0.004444

16 to 30 0.341 to 0.68 . . . 0.0042 0.0043 0.0045 0.0046 0.0048 0.0050 0.0051 0.0053 0.0055

� 5 to 15 0.12 to 0.38 . . . . . . 0.0036 0.0037 0.0038 0.0041 0.0041 0.0043 0.0044 0.004540

16 to 30 0.381 to 0.76 . . . . . . 0.0045 0.0046 0.0048 0.0050 0.0052 0.0053 0.0055 0.0057

� 5 to 15 0.14 to 0.42 . . . . . . 0.0037 0.0039 0.0040 0.0042 0.0043 0.0044 0.0045 0.004736

16 to 30 0.421 to 0.84 . . . . . . 0.0047 0.0049 0.0050 0.0052 0.0054 0.0055 0.0057 0.0059

� 5 to 15 0.16 to 0.47 . . . . . . 0.0030 0.0041 0.0042 0.0044 0.0045 0.0046 0.0047 0.004932

16 to 30 0.471 to 0.94 . . . . . . 0.0049 0.0051 0.0052 0.0055 0.0056 0.0058 0.0059 0.0061

� 5 to 15 0.18 to 0.54 . . . . . . . . . 0.0043 0.0044 0.0046 0.0048 0.0049 0.0050 0.005228

16 to 30 0.541 to 1.08 . . . . . . . . . 0.0054 0.0056 0.0058 0.0060 0.0061 0.0062 0.0065

� 5 to 15 0.19 to 0.56 . . . . . . . . . 0.0044 0.0045 0.0047 0.0048 0.0050 0.0051 0.005227

16 to 30 0.561 to 1.12 . . . . . . . . . 0.0055 0.0057 0.0059 0.0061 0.0062 0.0063 0.0066

� 5 to 15 0.21 to 0.62 . . . . . . . . . 0.0047 0.0048 0.0049 0.0051 0.0052 0.0053 0.005524

16 to 30 0.621 to 1.24 . . . . . . . . . 0.0058 0.0060 0.0062 0.0064 0.0065 0.0066 0.0069

� 5 to 15 0.25 to 0.75 . . . . . . . . . . . . 0.0052 0.0055 0.0056 0.0057 0.0057 0.005920

16 to 30 0.751 to 1.50 . . . . . . . . . . . . 0.0065 0.0067 0.0069 0.0072 0.0074 0.0074

� 5 to 15 0.28 to 0.83 . . . . . . . . . . . . . . . 0.0056 0.0059 0.0060 0.0060 0.006218

16 to 30 0.831 to 1.66 . . . . . . . . . . . . . . . 0.0070 0.0072 0.0074 0.0075 0.0077

� 5 to 15 0.31 to 0.94 . . . . . . . . . . . . . . . 0.0059 0.0061 0.0062 0.0063 0.006516

16 to 30 0.941 to 1.88 . . . . . . . . . . . . . . . 0.0074 0.0076 0.0077 0.0079 0.0081

� 5 to 15 0.36 to 1.07 . . . . . . . . . . . . . . . . . . 0.0065 0.0066 0.0067 0.006914

16 to 30 1.071 to 2.14 . . . . . . . . . . . . . . . . . . 0.0081 0.0082 0.0084 0.0086

� 5 to 15 0.42 to 1.25 . . . . . . . . . . . . . . . . . . 0.0070 0.0071 0.0072 0.007412

16 to 30 1.251 to 2.50 . . . . . . . . . . . . . . . . . . 0.0087 0.0088 0.0090 0.0092

� 5 to 15 0.50 to 1.50 . . . . . . . . . . . . . . . . . . . . . . . . 0.0078 0.008010

16 to 30 1.501 to 3.00 . . . . . . . . . . . . . . . . . . . . . . . . 0.0098 0.0100

� 5 to 15 0.62 to 1.88 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00898

16 to 30 1.881 to 3.76 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0111

� 5 to 15 0.83 to 2.50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

16 to 30 2.501 to 5.00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 1.25 to 3.75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

16 to 30 3.751 to 7.50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .





152



1.25 1.5 1.75 2 2.5 3 3.5 4 5 6 8 10 12

1.125 1.375 1.625 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11

1.375 1.625 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11 13


. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 80

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 72

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 64

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 56

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 48

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 44

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 40

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.0049 0.0050 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 360.0061 0.0062 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.0051 0.0052 0.0053 0.0054 0.0056 0.0058 . . . . . . . . . . . . . . . . . . . . . � 320.0063 0.0065 0.0066 0.0068 0.0070 0.0072 . . . . . . . . . . . . . . . . . . . . .

0.0053 0.0055 0.0056 0.0057 0.0059 0.0060 0.0062 0.0063 . . . . . . . . . . . . . . . � 280.0067 0.0068 0.0070 0.0071 0.0073 0.0075 0.0077 0.0079 . . . . . . . . . . . . . . .

0.0053 0.0055 0.0056 0.0057 0.0059 0.0061 0.0063 0.0064 0.0066 0.0068 . . . . . . . . . � 270.0067 0.0069 0.0071 0.0072 0.0074 0.0076 0.0078 0.0080 0.0083 0.0085 . . . . . . . . .

0.0056 0.0058 0.0059 0.0060 0.0062 0.0064 0.0065 0.0066 0.0069 0.0071 . . . . . . . . . � 240.0070 0.0072 0.0074 0.0075 0.0077 0.0079 0.0081 0.0083 0.0086 0.0089 . . . . . . . . .

0.0061 0.0062 0.0063 0.0064 0.0066 0.0068 0.0069 0.0070 0.0073 0.0075 . . . . . . . . . � 200.0076 0.0077 0.0079 0.0080 0.0083 0.0085 0.0086 0.0088 0.0091 0.0094 . . . . . . . . .

0.0063 0.0065 0.0066 0.0067 0.0069 0.0070 0.0072 0.0073 0.0076 0.0078 0.0081 . . . . . . � 180.0079 0.0081 0.0082 0.0083 0.0086 0.0088 0.0090 0.0091 0.0094 0.0097 0.0101 . . . . . .

0.0066 0.0068 0.0069 0.0070 0.0072 0.0073 0.0075 0.0076 0.0079 0.0081 0.0084 0.0087 . . . � 160.0083 0.0085 0.0086 0.0087 0.0090 0.0092 0.0094 0.0095 0.0098 0.0101 0.0105 0.0109 . . .

0.0070 0.0072 0.0073 0.0074 0.0076 0.0077 0.0079 0.0080 0.0083 0.0085 0.0088 0.0091 0.0094 � 140.0088 0.0089 0.0091 0.0092 0.0095 0.0097 0.0099 0.0100 0.0103 0.0106 0.0110 0.0114 0.0117

0.0075 0.0076 0.0078 0.0079 0.0081 0.0082 0.0084 0.0085 0.0087 0.0090 0.0093 0.0096 0.0099 � 120.0094 0.0096 0.0097 0.0098 0.0101 0.0103 0.0105 0.0106 0.0109 0.0112 0.0116 0.0120 0.0123

0.0082 0.0083 0.0084 0.0085 0.0087 0.0089 0.0090 0.0091 0.0094 0.0096 0.0100 0.0103 0.0105 � 100.0102 0.0104 0.0105 0.0106 0.0109 0.0111 0.0113 0.0114 0.0117 0.0120 0.0124 0.0128 0.0131

0.0090 0.0092 0.0093 0.0094 0.0096 0.0098 0.0099 0.0100 0.0103 0.0105 0.0108 0.0111 0.0114 � 80.0113 0.0115 0.0116 0.0118 0.0120 0.0122 0.0124 0.0125 0.0128 0.0131 0.0136 0.0139 0.0143

. . . 0.0105 0.0106 0.0108 0.0109 0.0111 0.0113 0.0114 0.0116 0.0118 0.0122 0.0125 0.0128 � 6

. . . 0.0132 0.0133 0.0134 0.0137 0.0139 0.0141 0.0142 0.0145 0.0148 0.0152 0.0156 0.0159

. . . . . . . . . 0.0131 0.0133 0.0135 0.0136 0.0138 0.0140 0.0142 0.0146 0.0149 0.0151 � 4

. . . . . . . . . 0.0164 0.0166 0.0168 0.0170 0.0172 0.0175 0.0178 0.0182 0.0186 0.0189



153







To and including 0.0781 0.1094 0.1562 0.2188 0.3125 0.4375 0.5625 0.6875 0.875 1.125



� 5 to 15 0.06 to 0.19 0.0019 0.0019 0.0020 0.0021 0.0022 . . . . . . . . . . . . . . .80

16 to 30 0.191 to 0.38 0.0023 0.0024 0.0025 0.0026 0.0027 . . . . . . . . . . . . . . .

� 5 to 15 0.07 to 0.21 0.0019 0.0020 0.0021 0.0022 0.0023 0.0024 . . . . . . . . . . . .72

16 to 30 0.211 to 0.42 0.0024 0.0025 0.0026 0.0027 0.0029 0.0030 . . . . . . . . . . . .

� 5 to 15 0.08 to 0.23 0.0020 0.0021 0.0022 0.0023 0.0024 0.0025 0.0026 . . . . . . . . .64

16 to 30 0.231 to 0.46 0.0026 0.0027 0.0027 0.0029 0.0030 0.0031 0.0033 . . . . . . . . .

� 5 to 15 0.09 to 0.27 . . . 0.0023 0.0023 0.0024 0.0025 0.0026 0.0027 0.0028 0.0029 . . .56

16 to 30 0.271 to 0.54 . . . 0.0028 0.0029 0.0030 0.0031 0.0033 0.0034 0.0035 0.0036 . . .

� 5 to 15 0.10 to 0.31 . . . 0.0024 0.0025 0.0026 0.0027 0.0028 0.0029 0.0030 0.0031 . . .48

16 to 30 0.311 to 0.62 . . . 0.0030 0.0031 0.0032 0.0033 0.0035 0.0036 0.0037 0.0038 . . .

� 5 to 15 0.11 to 0.34 . . . 0.0025 0.0026 0.0027 0.0028 0.0029 0.0030 0.0031 0.0032 0.003344

16 to 30 0.341 to 0.68 . . . 0.0031 0.0032 0.0033 0.0034 0.0036 0.0037 0.0039 0.0040 0.0041

� 5 to 15 0.12 to 0.38 . . . . . . 0.0027 0.0028 0.0029 0.0030 0.0031 0.0032 0.0033 0.003440

16 to 30 0.381 to 0.76 . . . . . . 0.0033 0.0035 0.0036 0.0037 0.0039 0.0040 0.0041 0.0043

� 5 to 15 0.14 to 0.42 . . . . . . 0.0028 0.0029 0.0030 0.0031 0.0032 0.0033 0.0034 0.003536

16 to 30 0.421 to 0.84 . . . . . . 0.0035 0.0036 0.0037 0.0039 0.0040 0.0042 0.0043 0.0044

� 5 to 15 0.16 to 0.47 . . . . . . 0.0030 0.0031 0.0031 0.0033 0.0034 0.0035 0.0036 0.003732

16 to 30 0.471 to 0.94 . . . . . . 0.0037 0.0038 0.0039 0.0041 0.0042 0.0043 0.0044 0.0046

� 5 to 15 0.18 to 0.54 . . . . . . . . . 0.0033 0.0033 0.0035 0.0036 0.0037 0.0037 0.003928

16 to 30 0.541 to 1.08 . . . . . . . . . 0.0041 0.0042 0.0043 0.0045 0.0046 0.0047 0.0048

� 5 to 15 0.19 to 0.56 . . . . . . . . . 0.0033 0.0034 0.0035 0.0036 0.0037 0.0038 0.003927

16 to 30 0.561 to 1.12 . . . . . . . . . 0.0041 0.0042 0.0044 0.0045 0.0046 0.0047 0.0049

� 5 to 15 0.21 to 0.62 . . . . . . . . . 0.0035 0.0036 0.0037 0.0038 0.0039 0.0040 0.004124

16 to 30 0.621 to 1.24 . . . . . . . . . 0.0044 0.0045 0.0046 0.0048 0.0049 0.0050 0.0051

� 5 to 15 0.25 to 0.75 . . . . . . . . . . . . 0.0039 0.0040 0.0041 0.0042 0.0043 0.004420

16 to 30 0.751 to 1.50 . . . . . . . . . . . . 0.0049 0.0050 0.0052 0.0053 0.0054 0.0055

� 5 to 15 0.28 to 0.83 . . . . . . . . . . . . . . . 0.0042 0.0043 0.0044 0.0045 0.004618

16 to 30 0.831 to 1.66 . . . . . . . . . . . . . . . 0.0053 0.0054 0.0055 0.0056 0.0058

� 5 to 15 0.31 to 0.94 . . . . . . . . . . . . . . . 0.0045 0.0046 0.0046 0.0047 0.004916

16 to 30 0.941 to 1.88 . . . . . . . . . . . . . . . 0.0056 0.0057 0.0058 0.0059 0.0061

� 5 to 15 0.36 to 1.07 . . . . . . . . . . . . . . . . . . 0.0049 0.0049 0.0050 0.005214

16 to 30 1.071 to 2.14 . . . . . . . . . . . . . . . . . . 0.0061 0.0062 0.0063 0.0064

� 5 to 15 0.42 to 1.25 . . . . . . . . . . . . . . . . . . 0.0052 0.0053 0.0054 0.005512

16 to 30 1.251 to 2.50 . . . . . . . . . . . . . . . . . . 0.0065 0.0066 0.0067 0.0069

� 5 to 15 0.50 to 1.50 . . . . . . . . . . . . . . . . . . . . . . . . 0.0059 0.006010

16 to 30 1.501 to 3.00 . . . . . . . . . . . . . . . . . . . . . . . . 0.0073 0.0075

� 5 to 15 0.62 to 1.88 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00678

16 to 30 1.881 to 3.76 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0083

� 5 to 15 0.83 to 2.50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

16 to 30 2.501 to 5.00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

� 5 to 15 1.25 to 3.75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

16 to 30 3.751 to 7.50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .




ances for 9 pitches taken to six decimal places by a factor of 1.21875 (obtained by multiplying the 0.975 factor by1.25). For lengths of engagement not tabulated, see para. 5.

154



1.25 1.5 1.75 2 2.5 3 3.5 4 5 6 8 10 12

1.125 1.375 1.625 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11

1.375 1.625 1.875 2.25 2.75 3.25 3.75 4.5 5.5 7 9 11 13


. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 80

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 72

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 64

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 56

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 48

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 44

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 40

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.0036 0.0037 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . � 360.0046 0.0047 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.0038 0.0039 0.0040 0.0041 0.0042 0.0043 . . . . . . . . . . . . . . . . . . . . . � 320.0048 0.0049 0.0050 0.0051 0.0053 0.0054 . . . . . . . . . . . . . . . . . . . . .

0.0040 0.0041 0.0042 0.0043 0.0044 0.0045 0.0046 0.0047 . . . . . . . . . . . . . . . � 280.0050 0.0051 0.0052 0.0053 0.0055 0.0057 0.0058 0.0059 . . . . . . . . . . . . . . .

0.0040 0.0041 0.0042 0.0043 0.0045 0.0046 0.0047 0.0048 0.0050 0.0051 . . . . . . . . . � 270.0051 0.0052 0.0053 0.0054 0.0056 0.0057 0.0059 0.0060 0.0062 0.0064 . . . . . . . . .

0.0042 0.0043 0.0044 0.0045 0.0046 0.0048 0.0049 0.0050 0.0052 0.0053 . . . . . . . . . � 240.0053 0.0054 0.0055 0.0056 0.0058 0.0060 0.0061 0.0062 0.0064 0.0066 . . . . . . . . .

0.0045 0.0046 0.0047 0.0048 0.0050 0.0051 0.0052 0.0053 0.0055 0.0056 . . . . . . . . . � 200.0057 0.0058 0.0059 0.0060 0.0062 0.0063 0.0065 0.0066 0.0068 0.0070 . . . . . . . . .

0.0047 0.0048 0.0049 0.0050 0.0051 0.0053 0.0054 0.0055 0.0057 0.0058 0.0061 . . . . . . � 180.0059 0.0060 0.0062 0.0063 0.0064 0.0066 0.0067 0.0069 0.0071 0.0073 0.0076 . . . . . .

0.0050 0.0051 0.0052 0.0052 0.0054 0.0055 0.0056 0.0057 0.0059 0.0061 0.0063 0.0066 . . . � 160.0062 0.0063 0.0065 0.0066 0.0067 0.0069 0.0070 0.0072 0.0074 0.0076 0.0079 0.0082 . . .

0.0053 0.0054 0.0055 0.0055 0.0057 0.0058 0.0059 0.0060 0.0062 0.0063 0.0066 0.0068 0.0070 � 140.0066 0.0067 0.0068 0.0069 0.0071 0.0072 0.0074 0.0075 0.0077 0.0079 0.0083 0.0086 0.0088

0.0056 0.0057 0.0058 0.0059 0.0060 0.0062 0.0063 0.0064 0.0066 0.0067 0.0070 0.0072 0.0074 � 120.0070 0.0072 0.0073 0.0074 0.0076 0.0077 0.0078 0.0080 0.0082 0.0084 0.0087 0.0090 0.0093

0.0061 0.0062 0.0063 0.0064 0.0065 0.0066 0.0068 0.0069 0.0070 0.0072 0.0075 0.0077 0.0079 � 100.0076 0.0078 0.0079 0.0080 0.0082 0.0083 0.0084 0.0086 0.0088 0.0090 0.0093 0.0096 0.0099

0.0068 0.0069 0.0070 0.0071 0.0072 0.0073 0.0074 0.0075 0.0077 0.0079 0.0081 0.0084 0.0086 � 80.0085 0.0086 0.0087 0.0088 0.0090 0.0091 0.0093 0.0094 0.0096 0.0098 0.0102 0.0104 0.0107

. . . 0.0079 0.0080 0.0081 0.0082 0.0083 0.0084 0.0085 0.0087 0.0089 0.0091 0.0094 0.0096 � 6

. . . 0.0090 0.0100 0.0101 0.0103 0.0104 0.0106 0.0107 0.0109 0.0111 0.0114 0.0117 0.0120

. . . . . . . . . 0.0098 0.0100 0.0101 0.0102 0.0103 0.0105 0.0107 0.0109 0.0111 0.0113 � 4

. . . . . . . . . 0.0123 0.0125 0.0126 0.0128 0.0129 0.0131 0.0133 0.0137 0.0139 0.0142



155



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157

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158

Tabl

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70

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0176

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79

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85

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53

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306

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70

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48

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88

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:(1

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Table D-11 Minor Diameter Tolerances for Internal Special Screw Threads(UNS/UNRS) — Class 3B

Tolerance based on basic major diameter of . . . 0.161 0.190 0.216 0.250 0.3125 0.375 0.4375 0.500 0.5625 0.625 0.6875

For diameter range above 0.053 0.151 0.177 0.203 0.233 0.281 0.344 0.406 0.469 0.531 0.594 0.656

To and including 0.151 0.177 0.203 0.233 0.281 0.344 0.406 0.469 0.531 0.594 0.656 0.719 All Larger(1) Diameters

Length of Eng. in Termsof Diameter [Note (2)]

Threads/ Tolerance To andin. Ratios Above Including Minor Diameter Tolerances, in. [Note (3)]

�0.5 0 0.33D . . . 0.0015 0.0013 0.0013 0.0013 0.0013 . . . . . . . . . . . . . . . . . . . . .0.75 0.33D 0.67D . . . 0.0022 0.0020 0.0020 0.0020 0.0020 . . . . . . . . . . . . . . . . . . . . .

801.0 0.67D 1.5D . . . 0.0030 0.0027 0.0026 0.0026 0.0026 . . . . . . . . . . . . . . . . . . . . .1.25 1.5D 3D . . . 0.0037 0.0033 0.0033 0.0033 0.0033 . . . . . . . . . . . . . . . . . . . . .

�0.5 0 0.33D . . . 0.0017 0.0015 0.0015 0.0015 0.0015 0.0015 0.0015 . . . . . . . . . . . . . . .0.75 0.33D 0.67D . . . 0.0026 0.0023 0.0022 0.0022 0.0022 0.0022 0.0022 . . . . . . . . . . . . . . .

721.0 0.67D 1.5D . . . 0.0034 0.0031 0.0029 0.0029 0.0029 0.0029 0.0029 . . . . . . . . . . . . . . .1.25 1.5D 3D . . . 0.0043 0.0039 0.0036 0.0036 0.0036 0.0036 0.0036 . . . . . . . . . . . . . . .

�0.5 0 0.33D . . . 0.0020 0.0018 0.0016 0.0016 0.0016 0.0016 0.0016 0.0016 0.0016 . . . . . . . . .0.75 0.33D 0.67D . . . 0.0030 0.0027 0.0025 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 . . . . . . . . .

641.0 0.67D 1.5D . . . 0.0040 0.0036 0.0033 0.0032 0.0032 0.0032 0.0032 0.0032 0.0032 . . . . . . . . .1.25 1.5D 3D . . . 0.0050 0.0045 0.0041 0.0040 0.0040 0.0040 0.0040 0.0040 0.0040 . . . . . . . . .

�0.5 0 0.33D . . . 0.0023 0.0021 0.0019 0.0018 0.0018 0.0018 0.0018 0.0018 0.0018 0.0018 0.0018 0.00180.75 0.33D 0.67D . . . 0.0035 0.0032 0.0029 0.0027 0.0027 0.0027 0.0027 0.0027 0.0027 0.0027 0.0027 0.0027

561.0 0.67D 1.5D . . . 0.0047 0.0042 0.0039 0.0036 0.0036 0.0036 0.0036 0.0036 0.0036 0.0036 0.0036 0.00361.25 1.5D 3D . . . 0.0059 0.0053 0.0049 0.0045 0.0045 0.0045 0.0045 0.0045 0.0045 0.0045 0.0045 0.0045

�0.5 0 0.33D . . . 0.0028 0.0025 0.0023 0.0021 0.0021 0.0021 0.0021 0.0021 0.0021 0.0021 0.0021 0.00210.75 0.33D 0.67D . . . 0.0042 0.0038 0.0035 0.0032 0.0031 0.0031 0.0031 0.0031 0.0031 0.0031 0.0031 0.0031

481.0 0.67D 1.5D . . . 0.0056 0.0051 0.0047 0.0043 0.0041 0.0041 0.0041 0.0041 0.0041 0.0041 0.0041 0.00411.25 1.5D 3D . . . 0.0070 0.0063 0.0059 0.0054 0.0052 0.0052 0.0052 0.0052 0.0052 0.0052 0.0052 0.0052

�0.5 0 0.33D . . . 0.0031 0.0028 0.0026 0.0024 0.0022 0.0022 0.0022 0.0022 0.0022 0.0022 0.0022 0.00220.75 0.33D 0.67D . . . 0.0046 0.0042 0.0039 0.0036 0.0033 0.0033 0.0033 0.0033 0.0033 0.0033 0.0033 0.0033

441.0 0.67D 1.5D . . . 0.0062 0.0056 0.0052 0.0047 0.0045 0.0045 0.0045 0.0045 0.0045 0.0045 0.0045 0.00451.25 1.5D 3D . . . 0.0077 0.0070 0.0065 0.0059 0.0056 0.0056 0.0056 0.0056 0.0056 0.0056 0.0056 0.0056

�0.5 0 0.33D . . . 0.0034 0.0031 0.0029 0.0026 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 0.00240.75 0.33D 0.67D . . . 0.0051 0.0047 0.0043 0.0040 0.0036 0.0036 0.0036 0.0036 0.0036 0.0036 0.0036 0.0036

401.0 0.67D 1.5D . . . 0.0068 0.0062 0.0057 0.0053 0.0048 0.0048 0.0048 0.0048 0.0048 0.0048 0.0048 0.00481.25 1.5D 3D . . . 0.0086 0.0078 0.0072 0.0066 0.0062 0.0062 0.0060 0.0060 0.0060 0.0060 0.0060 0.0060

�0.5 0 0.33D . . . 0.0038 0.0035 0.0032 0.0030 0.0026 0.0026 0.0026 0.0026 0.0026 0.0026 0.0026 0.00260.75 0.33D 0.67D . . . 0.0058 0.0052 0.0048 0.0044 0.0039 0.0039 0.0039 0.0039 0.0039 0.0039 0.0039 0.0039

361.0 0.67D 1.5D . . . 0.0077 0.0070 0.0064 0.0059 0.0053 0.0052 0.0052 0.0052 0.0052 0.0052 0.0052 0.00521.25 1.5D 3D . . . 0.0096 0.0087 0.0081 0.0074 0.0066 0.0065 0.0065 0.0065 0.0065 0.0065 0.0065 0.0065

�0.5 0 0.33D . . . 0.0043 0.0039 0.0036 0.0034 0.0030 0.0029 0.0029 0.0029 0.0029 0.0029 0.0029 0.00290.75 0.33D 0.67D . . . 0.0065 0.0059 0.0055 0.0050 0.0045 0.0043 0.0043 0.0043 0.0043 0.0043 0.0043 0.0043

321.0 0.67D 1.5D . . . 0.0087 0.0079 0.0073 0.0067 0.0060 0.0057 0.0057 0.0057 0.0057 0.0057 0.0057 0.00571.25 1.5D 3D . . . 0.0108 0.0099 0.0091 0.0084 0.0075 0.0072 0.0072 0.0072 0.0072 0.0072 0.0072 0.0072

�0.5 0 0.33D . . . . . . 0.0045 0.0042 0.0039 0.0034 0.0032 0.0032 0.0032 0.0032 0.0032 0.0032 0.00320.75 0.33D 0.67D . . . . . . 0.0068 0.0063 0.0058 0.0051 0.0047 0.0047 0.0047 0.0047 0.0047 0.0047 0.0047

281.0 0.67D 1.5D . . . . . . 0.0091 0.0084 0.0077 0.0069 0.0063 0.0063 0.0063 0.0063 0.0063 0.0063 0.00631.25 1.5D 3D . . . . . . 0.0113 0.0105 0.0096 0.0086 0.0079 0.0079 0.0079 0.0079 0.0079 0.0079 0.0079

�0.5 0 0.33D . . . . . . 0.0047 0.0044 0.0040 0.0036 0.0032 0.0032 0.0032 0.0032 0.0032 0.0032 0.00320.75 0.33D 0.67D . . . . . . 0.0071 0.0065 0.0060 0.0053 0.0048 0.0048 0.0048 0.0048 0.0048 0.0048 0.0048

271.0 0.67D 1.5D . . . . . . 0.0094 0.0087 0.0080 0.0071 0.0065 0.0065 0.0065 0.0065 0.0065 0.0065 0.00651.25 1.5D 3D . . . . . . 0.0118 0.0109 0.0100 0.0089 0.0081 0.0081 0.0081 0.0081 0.0081 0.0081 0.0081

�0.5 0 0.33D . . . . . . 0.0053 0.0049 0.0045 0.0040 0.0037 0.0035 0.0035 0.0035 0.0035 0.0035 0.00350.75 0.33D 0.67D . . . . . . 0.0079 0.0073 0.0068 0.0060 0.0055 0.0052 0.0052 0.0052 0.0052 0.0052 0.0052

241.0 0.67D 1.5D . . . . . . 0.0106 0.0098 0.0090 0.0080 0.0073 0.0070 0.0070 0.0070 0.0070 0.0070 0.00701.25 1.5D 3D . . . . . . 0.0132 0.0122 0.0113 0.0100 0.0092 0.0087 0.0087 0.0087 0.0087 0.0087 0.0087

�0.5 0 0.33D . . . . . . . . . . . . 0.0054 0.0048 0.0044 0.0041 0.0039 0.0039 0.0039 0.0039 0.00390.75 0.33D 0.67D . . . . . . . . . . . . 0.0081 0.0072 0.0066 0.0062 0.0058 0.0058 0.0058 0.0058 0.0058

201.0 0.67D 1.5D . . . . . . . . . . . . 0.0108 0.0096 0.0088 0.0082 0.0078 0.0078 0.0078 0.0078 0.00781.25 1.5D 3D . . . . . . . . . . . . 0.0135 0.0120 0.0110 0.0103 0.0097 0.0097 0.0097 0.0097 0.0097

�0.5 0 0.33D . . . . . . . . . . . . . . . 0.0053 0.0049 0.0045 0.0043 0.0041 0.0041 0.0041 0.00410.75 0.33D 0.67D . . . . . . . . . . . . . . . 0.0080 0.0073 0.0068 0.0065 0.0062 0.0061 0.0061 0.0061

181.0 0.67D 1.5D . . . . . . . . . . . . . . . 0.0106 0.0097 0.0091 0.0086 0.0082 0.0081 0.0081 0.00811.25 1.5D 3D . . . . . . . . . . . . . . . 0.0133 0.0122 0.0114 0.0108 0.0103 0.0102 0.0102 0.0102

�0.5 0 0.33D . . . . . . . . . . . . . . . . . . 0.0054 0.0051 0.0048 0.0046 0.0044 0.0043 0.00430.75 0.33D 0.67D . . . . . . . . . . . . . . . . . . 0.0082 0.0076 0.0072 0.0069 0.0067 0.0064 0.0064

161.0 0.67D 1.5D . . . . . . . . . . . . . . . . . . 0.0109 0.0102 0.0096 0.0092 0.0089 0.0086 0.00851.25 1.5D 3D . . . . . . . . . . . . . . . . . . 0.0136 0.0127 0.0120 0.0115 0.0111 0.0108 0.0106

159




Table D-11 Minor Diameter Tolerances for Internal Special Screw Threads(UNS/UNRS) — Class 3B (Cont’d)

Tolerance based on basic major diameter of 0.0375 0.4375 0.500 0.5625 0.625 0.6875 0.750 0.8125 0.875 0.9375

For diameter range above 0.0344 0.406 0.469 0.531 0.594 0.656 0.719 0.781 0.844 0.906All Larger

To and including 0.406 0.469 0.531 0.594 0.656 0.719 0.781 0.844 0.906 0.969 Diameters

Length of Eng. in Termsof Diam. [Note (2)]

Threads/ Tolerance To andin. Ratios Above Including Minor Diameter Tolerances, in. [Note (3)]

�0.5 0 0.33D . . . 0.0058 0.0054 0.0052 0.0050 0.0049 0.0047 0.0046 0.0045 0.0044 0.00440.75 0.33D 0.67D . . . 0.0086 0.0082 0.0078 0.0075 0.0073 0.0071 0.0069 0.0068 0.0067 0.0066

141.0 0.67D 1.5D . . . 0.0115 0.0109 0.0104 0.0100 0.0097 0.0095 0.0092 0.0091 0.0089 0.00881.25 1.5D 3D . . . 0.0144 0.0136 0.0130 0.0125 0.0122 0.0118 0.0116 0.0113 0.0111 0.0110

�0.5 0 0.33D . . . . . . 0.0058 0.0056 0.0054 0.0052 0.0050 0.0050 0.0049 0.0048 0.00470.75 0.33D 0.67D . . . . . . 0.0087 0.0083 0.0080 0.0078 0.0076 0.0074 0.0073 0.0071 0.0070

131.0 0.67D 1.5D . . . . . . 0.0117 0.0111 0.0107 0.0104 0.0101 0.0099 0.0097 0.0095 0.00941.25 1.5D 3D . . . . . . 0.0146 0.0139 0.0134 0.0130 0.0126 0.0124 0.0122 0.0119 0.0118

�0.5 0 0.33D . . . . . . 0.0063 0.0060 0.0058 0.0056 0.0054 0.0053 0.0052 0.0051 0.00500.75 0.33D 0.67D . . . . . . 0.0094 0.0090 0.0087 0.0084 0.0082 0.0080 0.0078 0.0077 0.0075

121.0 0.67D 1.5D . . . . . . 0.0125 0.0120 0.0115 0.0112 0.0109 0.0106 0.0104 0.0102 0.01001.25 1.5D 3D . . . . . . 0.0157 0.0150 0.0144 0.0140 0.0136 0.0133 0.0130 0.0128 0.0125

�0.5 0 0.33D . . . . . . . . . . . . 0.0062 0.0060 0.0058 0.0058 0.0056 0.0055 0.00540.75 0.33D 0.67D . . . . . . . . . . . . 0.0094 0.0091 0.0088 0.0086 0.0084 0.0082 0.0082

111.0 0.67D 1.5D . . . . . . . . . . . . 0.0125 0.0121 0.0177 0.0115 0.0112 0.0110 0.01091.25 1.5D 3D . . . . . . . . . . . . 0.0156 0.0151 0.0146 0.0144 0.0140 0.0138 0.0136

�0.5 0 0.33D . . . . . . . . . . . . . . . 0.0066 0.0064 0.0062 0.0061 0.0060 0.00600.75 0.33D 0.67D . . . . . . . . . . . . . . . 0.0099 0.0096 0.0093 0.0092 0.0090 0.0090

101.0 0.67D 1.5D . . . . . . . . . . . . . . . 0.0131 0.0128 0.0125 0.0122 0.0120 0.01201.25 1.5D 3D . . . . . . . . . . . . . . . 0.0164 0.0160 0.0156 0.0153 0.0150 0.0150

�0.5 0 0.33D . . . . . . . . . . . . . . . . . . . . . 0.0068 0.0067 0.0066 0.00660.75 0.33D 0.67D . . . . . . . . . . . . . . . . . . . . . 0.0103 0.0100 0.0100 0.0100

91.0 0.67D 1.5D . . . . . . . . . . . . . . . . . . . . . 0.0137 0.0134 0.0133 0.01331.25 1.5D 3D . . . . . . . . . . . . . . . . . . . . . 0.0171 0.0168 0.0166 0.0166

�0.5 0 0.33D . . . . . . . . . . . . . . . . . . . . . 0.0075 0.0075 0.0075 0.00750.75 0.33D 0.67D . . . . . . . . . . . . . . . . . . . . . 0.0112 0.0112 0.0112 0.0112

81.0 0.67D 1.5D . . . . . . . . . . . . . . . . . . . . . 0.0150 0.0150 0.0150 0.01501.25 1.5D 3D . . . . . . . . . . . . . . . . . . . . . 0.0188 0.0188 0.0188 0.0188

�0.5 0 0.33D . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0086 0.00860.75 0.33D 0.67D . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0129 0.0129

71.0 0.67D 1.5D . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0171 0.01711.25 1.5D 3D . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0214 0.0214

�0.5 0 0.33D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.01000.75 0.33D 0.67D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0150

61.0 0.67D 1.5D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02001.25 1.5D 3D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0250

�0.5 0 0.33D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.01200.75 0.33D 0.67D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0180

51.0 0.67D 1.5D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02401.25 1.5D 3D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0300

�0.5 0 0.33D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.01330.75 0.33D 0.67D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0200

4.51.0 0.67D 1.5D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02671.25 1.5D 3D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0333

�0.5 0 0.33D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.01500.75 0.33D 0.67D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0225

41.0 0.67D 1.5D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.03001.25 1.5D 3D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0375

NOTES:(1) For 0.151 in. diameter sizes and smaller, tolerance values for all three classes are the same. For smaller sizes, toler-

ance values are given in Table D-10.(2) Tolerances for lengths of engagement in terms of pitch should be selected from equivalent lengths of engagement in

terms of diameter ranges.(3) If the minor diameter tolerance as selected from this Table is less than the pitch diameter tolerance, use the latter.

160

ASME B1.1-2003

NONMANDATORY APPENDIX ECHANGES TO ASME B1.1-1989 TABLES 3A AND 3B

This Appendix contains Tables E-1 and E-2, whichshow the thread sizes that were listed in the previousrevisions of ASME B1.1, Tables 3A and 3B, respectively.Those areas in which no data is listed are identical todata in Tables 2 and D-1 in this Standard.

161



162

Tabl

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Tabl

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Thre

ads/

in.

Des

igna

tion

Clas

sA

llow

ance

Max

.M

in.

Min

.M

ax.

Min

.To

lera

nce

Max

.(R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

1–

64or

0.07

3–

64U

NC

2A..

...

...

...

...

...

...

...

.2B

...

0.06

23..

...

...

...

.3A

...

...

...

...

...

...

...

...

3B..

.0.

0623

...

...

...

...

1–

72or

0.07

3–

72U

NF

2A..

...

...

...

...

...

...

...

.2B

...

0.06

35..

...

...

...

.3A

...

...

...

...

...

...

...

...

3B..

.0.

0635

...

...

...

...

2–

64or

0.08

6–

64U

NF

2A..

...

...

...

...

...

...

...

.2B

...

0.07

53..

...

...

...

.3A

...

...

...

...

...

...

...

...

3B..

.0.

0753

...

...

...

...

6–

32or

0.13

8–

32U

NC

3A..

...

...

...

...

...

...

...

.3B

...

0.11

40..

...

...

...

.

8–

32or

0.16

4–

32U

NC

3A..

...

...

...

...

...

...

...

.3B

...

0.13

89..

...

...

...

.

10–

24or

0.19

0–

24U

NC

2A..

...

...

...

...

...

...

...

.2B

...

0.15

6..

...

...

...

.

12–

32or

0.21

6–

32U

NEF

2A0.

0009

0.21

510.

2091

...

0.19

480.

1917

0.00

31..

.2B

...

...

...

...

...

...

5 ⁄ 16

–20

or0.

3125

–20

UN

2A..

...

...

...

...

.0.

2748

0.00

40..

.2B

...

...

...

0.28

520.

0052

...

3A..

...

...

...

...

...

...

...

.3B

...

...

...

0.28

390.

0039

...

5 ⁄ 16

–28

or0.

3125

–28

UN

2A..

...

...

...

...

.0.

2849

0.00

34..

.2B

...

...

...

0.29

370.

0044

...

3A..

...

...

...

...

...

...

...

.3B

...

...

...

0.29

260.

0033

...

5 ⁄ 16

–32

or0.

3125

–32

UN

EF2A

...

...

...

...

...

0.28

800.

0032

...

2B..

...

...

.0.

2964

0.00

42..

.3A

...

...

...

...

...

0.28

980.

0024

...

3B..

.0.

2847

...

0.29

530.

0031

7 ⁄ 16

–16

or0.

4375

–16

UN

2A..

...

...

...

...

...

...

...

.2B

...

...

...

0.40

280.

0059

...

3A..

...

...

...

...

.0.

3935

0.00

34..

.3B

...

...

...

...

...

...

7 ⁄ 16

–20

or0.

4375

–20

UN

F1A

...

...

...

...

...

0.39

750.

0062

...

1B..

...

...

...

...

...

.

7 ⁄ 16

–28

or0.

4375

–28

UN

EF2A

...

...

...

...

...

...

...

...

2B..

...

...

.0.

4189

0.00

46..

.

7 ⁄ 16

–32

or0.

4375

–32

UN

3A..

...

...

...

...

.0.

4147

0.00

25..

.3B

...

...

...

...

...

...

1 ⁄ 2–

16or

0.50

0–

16U

N3A

...

...

...

...

...

...

...

...

3B..

.0.

4419

...

...

...

...

9 ⁄ 16

–16

or0.

5625

–16

UN

3A..

...

...

...

...

...

...

...

.3B

...

0.50

40..

...

...

...

.

9 ⁄ 16

–20

or0.

5625

–20

UN

2A..

...

...

...

...

.0.

5245

0.00

42..

.2B

...

...

...

0.53

550.

0055

...

3A..

...

...

...

...

...

...

...

.3B

...

0.51

62..

.0.

5341

0.00

41..

.

ASME B1.1-2003 NONMANDATORY APPENDIX E

163

Tabl

eE-

1Li

mit

sas

List

edin

Tabl

e2

(For

mer

ly3A

)Pr

ior

toAS

ME

B1.

1-20

03Ed

itio

n(C

ont’

d)

Exte

rnal

Inte

rnal

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

Func

tion

alD

iam

eter

Min

orFu

ncti

onal

Dia

met

erU

NR

Min

orM

ajor

Maj

orD

iam

eter

[Not

e(1

)]D

iam

eter

[Not

e(1

)]N

omin

alS

ize

and

Ser

ies

Dia

met

er,

Dia

met

er,

Thre

ads/

in.

Des

igna

tion

Clas

sA

llow

ance

Max

.M

in.

Min

.M

ax.

Min

.To

lera

nce

Max

.(R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

9 ⁄ 16

–24

or0.

5625

–24

UN

EF2A

...

...

...

...

...

0.53

030.

0039

...

2B..

...

...

...

...

...

.3A

...

...

...

...

...

0.53

250.

0029

...

3B..

...

...

.0.

5392

0.00

38..

.

9 ⁄ 16

–32

or0.

5625

–32

UN

2A0.

0010

0.56

150.

5555

...

0.54

120.

5377

...

...

2B..

...

...

.0.

5467

0.00

45..

.

5 ⁄ 8–

11or

0.62

5–

11U

NC

1A0.

0016

0.62

340.

6052

0.56

440.

5561

...

...

...

1B..

...

...

...

...

...

.2A

0.00

160.

6234

0.61

13..

.0.

5644

0.55

89..

...

.2B

...

...

...

...

...

...

5 ⁄ 8–

32or

0.62

5–

32U

N2A

...

...

...

...

...

...

...

...

2B..

.0.

590

...

...

...

...

11⁄ 1

6–

12or

0.68

75–

12U

N2A

...

...

...

...

...

0.62

640.

0054

...

2B..

...

...

...

...

...

.

11⁄ 1

6–

16or

0.68

75–

16U

N2A

...

...

...

...

...

...

...

...

2B..

...

...

.0.

6531

0.00

62..

.

11⁄ 1

6–

20or

0.68

75–

20U

N2A

...

...

...

...

...

0.64

940.

0043

...

2B..

...

...

.0.

6606

0.00

56..

.3A

...

...

...

...

...

0.65

180.

0032

...

3B..

.0.

6412

...

0.65

920.

0042

...

11⁄ 1

6–

24or

0.68

75–

24U

NEF

2A..

...

...

...

...

...

...

...

.2B

...

...

...

0.66

560.

0052

...

11⁄ 1

6–

28or

0.68

75–

28U

N3A

...

...

...

...

...

0.66

150.

0028

...

3B..

...

...

...

...

...

.

11⁄ 1

6–

32or

0.68

75–

32U

N2A

...

...

...

...

...

...

...

...

2B..

...

...

.0.

6718

0.00

46..

.

3 ⁄ 4–

16or

0.75

0–

16U

NF

3A..

...

...

...

...

...

...

...

.3B

...

0.69

08..

...

...

...

.

3 ⁄ 4–

20or

0.75

0–

20U

NEF

3A..

...

...

...

...

...

...

...

.3B

...

0.70

37..

...

...

...

.

3 ⁄ 4–

28or

0.75

0–

28U

N3A

...

...

...

...

...

...

...

0.70

743B

...

...

...

...

...

...

13⁄ 1

6–

12or

0.81

25–

12U

N2A

...

...

...

...

...

0.75

120.

0055

...

2B..

...

...

...

...

...

.3A

...

...

...

...

...

0.75

430.

0041

...

3B..

...

...

...

...

...

.

13⁄ 1

6–

16or

0.81

25–

16U

N2A

...

...

...

...

...

...

...

...

2B..

...

...

.0.

7782

0.00

63..

.3A

...

...

...

...

...

0.76

830.

0036

...

3B..

.0.

7533

...

...

0.00

47..

.

13⁄ 1

6–

20or

0.81

25–

20U

NEF

2A..

...

...

...

...

...

...

...

.2B

...

...

...

0.78

570.

0057

...

3A..

...

...

...

...

...

...

...

.3B

...

0.76

62..

...

...

...

.

13⁄ 1

6–

28or

0.81

25–

28U

N2A

...

...

...

...

...

0.78

430.

0038

...

2B..

...

...

...

...

...

.3A

...

...

...

...

...

...

...

...

3B..

...

...

.0.

7930

0.00

37..

.

NONMANDATORY APPENDIX E ASME B1.1-2003



164

Tabl

eE-

1Li

mit

sas

List

edin

Tabl

e2

(For

mer

ly3A

)Pr

ior

toAS

ME

B1.

1-20

03Ed

itio

n(C

ont’

d)

Exte

rnal

Inte

rnal

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

Func

tion

alD

iam

eter

Min

orFu

ncti

onal

Dia

met

erU

NR

Min

orM

ajor

Maj

orD

iam

eter

[Not

e(1

)]D

iam

eter

[Not

e(1

)]N

omin

alS

ize

and

Ser

ies

Dia

met

er,

Dia

met

er,

Thre

ads/

in.

Des

igna

tion

Clas

sA

llow

ance

Max

.M

in.

Min

.M

ax.

Min

.To

lera

nce

Max

.(R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

13⁄ 1

6–

32or

0.81

25–

32U

N2A

...

...

...

...

...

0.78

750.

0036

...

2B..

...

...

.0.

7969

0.00

47..

.3A

...

...

...

...

...

0.78

950.

0027

...

3B..

...

...

...

...

...

.

7 ⁄ 8–

12or

0.87

5–

12U

N2A

...

...

...

...

...

0.81

370.

0055

...

2B..

...

...

.0.

8281

0.00

72..

.3A

...

...

...

...

...

0.81

68..

...

.3B

...

0.79

48..

.0.

8263

0.00

54..

.

7 ⁄ 8–

14or

0.87

5–

14U

NF

1A..

...

...

...

...

...

...

...

.1B

...

0.81

4..

...

...

...

.2A

...

...

...

...

...

...

...

...

2B..

.0.

814

...

...

...

...

3A..

...

...

...

...

...

...

...

.3B

...

0.80

68..

...

...

...

.

7 ⁄ 8–

16or

0.87

5–

16U

N2A

...

...

...

...

...

...

...

...

2B..

...

...

.0.

8407

0.00

63..

.3A

...

...

...

...

...

0.83

080.

0036

...

3B..

.0.

8158

...

0.83

910.

0047

...

7 ⁄ 8–

20or

0.87

5–

20U

NEF

2A..

...

...

...

...

.0.

8368

0.00

44..

.2B

...

...

...

0.84

820.

0057

...

3A..

...

...

...

...

.0.

8392

0.00

33..

.3B

...

0.82

87..

.0.

8468

0.00

43..

.

7 ⁄ 8–

28or

0.87

5–

28U

N2A

...

...

...

...

...

0.84

680.

0038

...

2B..

...

...

.0.

8568

0.00

50..

.3A

...

...

...

...

...

...

...

...

3B..

...

...

.0.

8555

0.00

37..

.

7 ⁄ 8–

32or

0.87

5–

32U

N2A

...

...

...

...

...

0.85

000.

0036

...

2B..

...

...

.0.

8594

0.00

47..

.3A

...

...

...

...

...

0.85

200.

0027

...

3B..

...

...

...

...

...

.

15⁄ 1

6–

12or

0.93

75–

12U

N2A

...

...

...

...

...

0.87

600.

0057

...

2B..

...

...

.0.

8908

0.00

74..

.3A

...

...

...

...

...

0.87

930.

0041

...

3B..

...

...

...

...

...

.

15⁄ 1

6–

16or

0.93

75–

16U

N2A

...

...

...

...

...

...

...

...

2B..

...

...

.0.

9034

0.00

65..

.3A

...

...

...

...

...

...

...

...

3B..

.0.

8783

...

0.90

180.

0049

...

15⁄ 1

6–

20or

0.93

75–

20U

NEF

3A..

...

...

...

...

...

...

...

.3B

...

0.89

12..

...

...

...

.

15⁄ 1

6–

28or

0.93

75–

28U

N2A

...

...

...

...

...

0.90

910.

0040

...

2B..

...

...

.0.

9195

0.00

52..

.3A

...

...

...

...

...

...

...

...

3B..

...

...

.0.

9182

0.00

39..

.

1–

8or

1.00

0–

8U

NC

2A..

...

...

...

...

.0.

9100

...

...

2B..

...

...

...

...

...

.

1–

14or

1.00

0–

14U

NS

2A0.

0017

0.99

830.

9880

...

0.95

190.

9463

0.00

56..

.2B

...

...

...

0.96

090.

0073

...

3A..

...

...

...

...

.0.

9494

0.00

42..

.3B

...

...

...

0.95

900.

0054

...

11 ⁄ 16

–12

or1.

0625

–12

UN

3A..

...

...

...

...

.1.

0042

0.00

42..

.3B

...

...

...

...

...

...

11 ⁄ 16

–16

or1.

0625

–16

UN

3A..

...

...

...

...

.1.

0182

0.00

37..

.3B

...

1.00

33..

...

...

...

.


165

Tabl

eE-

1Li

mit

sas

List

edin

Tabl

e2

(For

mer

ly3A

)Pr

ior

toAS

ME

B1.

1-20

03Ed

itio

n(C

ont’

d)

Exte

rnal

Inte

rnal

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

Func

tion

alD

iam

eter

Min

orFu

ncti

onal

Dia

met

erU

NR

Min

orM

ajor

Maj

orD

iam

eter

[Not

e(1

)]D

iam

eter

[Not

e(1

)]N

omin

alS

ize

and

Ser

ies

Dia

met

er,

Dia

met

er,

Thre

ads/

in.

Des

igna

tion

Clas

sA

llow

ance

Max

.M

in.

Min

.M

ax.

Min

.To

lera

nce

Max

.(R

ef.)

Clas

sM

in.

Max

.M

in.

Max

.To

lera

nce

Min

.

11 ⁄ 16

–18

or1.

0625

–18

UN

EF2A

...

...

...

...

...

1.02

030.

0047

...

2B..

...

...

...

...

...

.3A

...

...

...

...

...

...

...

...

3B..

...

...

.1.

0310

0.00

46..

.

11 ⁄ 16

–20

or1.

0625

–20

UN

2A..

...

...

...

...

.1.

0241

0.00

45..

.2B

...

...

...

...

...

...

3A..

...

...

...

...

...

...

...

.3B

...

1.01

62..

.1.

0344

0.00

44..

.

11 ⁄ 8–

7or

1.12

5–

7U

NC

2A..

...

...

...

...

...

.0.

0072

...

2B..

...

...

...

...

...

.

11 ⁄ 8–

16or

1.12

5–

16U

N2A

...

...

...

...

...

...

...

...

2B..

...

...

.1.

0909

0.00

65..

.3A

...

...

...

...

...

1.08

070.

0037

...

3B..

.1.

0658

...

...

...

...

11 ⁄ 8–

18or

1.12

5–

18U

NEF

2A..

...

...

...

...

.1.

0828

0.00

47..

.2B

...

...

...

...

...

...

3A..

...

...

...

...

...

...

...

.3B

...

...

...

1.09

350.

0046

...

11 ⁄ 8–

20or

1.12

5–

20U

N2A

...

...

...

...

...

1.08

660.

0045

...

2B..

...

...

.1.

0984

0.00

59..

.3A

...

...

...

...

...

1.08

910.

0034

...

3B..

.1.

0787

...

1.09

690.

0044

...

13 ⁄ 16

–12

or1.

1875

–12

UN

2A..

...

...

...

...

.1.

1259

0.00

58..

.2B

...

...

...

...

...

...

13 ⁄ 16

–16

or1.

1875

–16

UN

3A..

...

...

...

...

...

...

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169

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27 ⁄ 8–

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27 ⁄ 8–

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27 ⁄ 8–

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31 ⁄ 8–

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31 ⁄ 8–

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31 ⁄ 4–

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31 ⁄ 4–

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33 ⁄ 8–

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33 ⁄ 8–

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3.37

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31 ⁄ 2–

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35 ⁄ 8–

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35 ⁄ 8–

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33 ⁄ 4–

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33 ⁄ 4–

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3.75

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37 ⁄ 8–

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41 ⁄ 8–

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41 ⁄ 8–

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41 ⁄ 4–

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41 ⁄ 4–

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43 ⁄ 8–

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43 ⁄ 8–

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41 ⁄ 2–

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41 ⁄ 2–

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45 ⁄ 8–

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45 ⁄ 8–

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43 ⁄ 4–

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43 ⁄ 4–

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43 ⁄ 4–

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47 ⁄ 8–

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47 ⁄ 8–

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51 ⁄ 8–

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51 ⁄ 8–

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51 ⁄ 4–

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51 ⁄ 2–

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172

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55 ⁄ 8–

8or

5.62

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5536

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55 ⁄ 8–

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5.62

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0.00

215.

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55 ⁄ 8–

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53 ⁄ 4–

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53 ⁄ 4–

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5.75

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53 ⁄ 4–

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5.75

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57 ⁄ 8–

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57 ⁄ 8–

12or

5.87

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...

...

...

...

...

...

2B..

...

...

.5.

8299

0.00

90..

.

57 ⁄ 8–

16or

5.87

5–

16U

N3A

...

...

...

...

...

5.82

970.

0047

...

3B..

.5.

8158

...

5.84

050.

0061

...

6–

8or

6.00

0–

8U

N2A

0.00

315.

9969

5.98

19..

.5.

9157

5.90

55..

...

.2B

...

...

...

5.93

210.

0131

...

3A..

...

...

...

...

.5.

9111

0.00

77..

.3B

...

...

...

5.92

870.

0099

...

6–

16or

6.00

0–

16U

N3A

...

...

...

...

...

...

...

...

3B..

.5.

9408

...

...

...

...

GEN

ERA

LN

OTE

S:

(a)

The

limit

slis

ted

inth

isTa

ble

are

nolo

nger

cons

ider

edst

anda

rdan

dar

efo

rin

form

atio

non

ly.

They

have

been

repl

aced

beca

use

ofca

lcul

atio

ner

rors

and

ach

ange

inro

undi

ngm

etho

ds.

(b)

Prod

uct

thre

ads,

gage

s,or

tool

ing

that

conf

orm

orw

ere

gene

rate

dus

ing

limit

slis

ted

inth

isTa

ble

shou

ldbe

cons

ider

edac

cept

able

.W

hen

repl

acin

g,th

ene

wlim

its

shou

ldbe

used

.(c

)It

isre

com

men

ded

that

all

user

spr

epar

efo

rth

eev

entu

alad

opti

onof

only

the

valu

esin

Tabl

e2.

NO

TE:

(1)

See

para

.5.

2.1

for

Func

tion

alD

iam

eter

.


173

Tabl

eE-

2Li

mit

sas

List

edin

Tabl

eD

-1(F

orm

erly

3B)P

rior

toAS

ME

B1.

1-20

03Ed

itio

n

Exte

rnal

Inte

rnal

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

Func

tion

alD

iam

eter

Func

tion

alD

iam

eter

UN

RM

inor

Maj

orM

ajor

Dia

met

er[N

ote

(1)]

Min

orD

iam

eter

[Not

e(1

)]N

omin

alS

ize

and

Ser

ies

Dia

met

er,

Dia

met

er,

Thre

ads/

in.

Des

igna

tion

Clas

sA

llow

ance

Max

.M

in.

Max

.M

in.

Tole

ranc

eM

ax.

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

Tole

ranc

eM

in.

10–

28or

0.19

0–

28U

NS

2A..

...

...

...

...

...

.0.

1464

2B..

...

...

...

...

...

.

10–

36or

0.19

0–

36U

NS

2A..

...

...

...

...

...

...

.2B

...

0.16

6..

...

...

...

.

10–

40or

0.19

0–

40U

NS

2A..

...

...

...

...

...

.0.

1592

2B..

...

...

...

...

...

.

10–

48or

0.19

0–

48U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

10–

56or

0.19

0–

56U

NS

2A..

...

...

...

...

...

.0.

1681

2B..

...

...

...

...

...

.

12–

36or

0.21

6–

36U

NS

2A..

...

...

...

...

...

.0.

1821

2B..

.0.

192

...

...

...

...

12–

40or

0.21

6–

40U

NS

2A..

...

...

...

...

...

.0.

1835

2B..

...

...

.0.

2035

0.00

37..

.

12–

48or

0.21

6–

48U

NS

2A..

...

...

...

.0.

1991

0.00

26..

.2B

...

...

...

0.20

590.

0034

...

12–

56or

0.21

6–

56U

NS

2A0.

0007

0.21

530.

2112

0.20

370.

2012

...

0.19

412B

...

...

...

0.20

760.

0032

...

1 ⁄ 4–

24or

0.25

0–

24U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

1 ⁄ 4–

27or

0.25

0–

27U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

1 ⁄ 4–

36or

0.25

0–

36U

NS

2A..

...

...

...

...

...

.0.

2161

2B..

.0.

226

...

...

...

...

1 ⁄ 4–

40or

0.25

0–

40U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

1 ⁄ 4–

48or

0.25

0–

48U

NS

2A..

...

...

...

...

...

.0.

2243

2B..

...

...

...

...

...

.

1 ⁄ 4–

56or

0.25

0–

56U

NS

2A..

...

...

...

...

...

.0.

2280

2B..

...

...

...

...

...

.

5 ⁄ 16

–27

or0.

3125

–27

UN

S2A

0.00

100.

3115

0.30

480.

2874

0.28

390.

0035

0.26

742B

...

...

...

0.29

290.

0045

...

5 ⁄ 16

–36

or0.

3125

–36

UN

S2A

...

...

...

...

...

...

...

2B..

...

...

.0.

2985

0.00

40..

.

5 ⁄ 16

–40

or0.

3125

–40

UN

S2A

...

...

...

...

0.29

250.

0029

...

2B..

...

...

.0.

3001

0.00

38..

.

5 ⁄ 16

–48

or0.

3125

–48

UN

S2A

...

...

...

...

0.29

550.

0027

...

2B..

...

...

...

...

...

.

3 ⁄ 8–

18or

0.37

5–

18U

NS

2A..

...

...

...

...

...

.0.

3076

2B..

...

...

...

...

...

.

3 ⁄ 8–

27or

0.37

5–

27U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...




174

Tabl

eE-

2Li

mit

sas

List

edin

Tabl

eD

-1(F

orm

erly

3B)P

rior

toAS

ME

B1.

1-20

03Ed

itio

n(C

ont’

d)

Exte

rnal

Inte

rnal

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

Func

tion

alD

iam

eter

Func

tion

alD

iam

eter

UN

RM

inor

Maj

orM

ajor

Dia

met

er[N

ote

(1)]

Min

orD

iam

eter

[Not

e(1

)]N

omin

alS

ize

and

Ser

ies

Dia

met

er,

Dia

met

er,

Thre

ads/

in.

Des

igna

tion

Clas

sA

llow

ance

Max

.M

in.

Max

.M

in.

Tole

ranc

eM

ax.

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

Tole

ranc

eM

in.

3 ⁄ 8–

36or

0.37

5–

36U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

3 ⁄ 8–

40or

0.37

5–

40U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

0.39

0–

27or

0.39

0–

27U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

7 ⁄ 16

–18

or0.

4375

–18

UN

S2A

...

...

...

...

0.39

580.

0043

0.37

012B

...

...

...

0.40

700.

0056

...

7 ⁄ 16

–24

or0.

4375

–24

UN

S2A

0.00

110.

4364

0.42

920.

4093

0.40

550.

0038

0.38

682B

...

...

...

0.41

530.

0049

...

7 ⁄ 16

–27

or0.

4375

–27

UN

S2A

...

...

...

...

0.40

870.

0036

...

2B..

...

...

.0.

4181

0.00

47..

.

1 ⁄ 2–

12or

0.50

0–

12U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

3A..

...

...

...

...

...

...

.3B

...

0.42

2..

...

...

...

.

1 ⁄ 2–

14or

0.50

0–

14U

NS

2A..

...

...

...

...

...

.0.

4135

2B..

...

...

...

...

...

.

1 ⁄ 2–

18or

0.50

0–

18U

NS

2A..

...

...

...

...

...

.0.

4326

2B..

...

...

...

...

...

.

1 ⁄ 2–

24or

0.50

0–

24U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

1 ⁄ 2–

27or

0.50

0–

27U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

9 ⁄ 16

–14

or0.

5625

–14

UN

S2A

...

...

...

...

...

...

0.47

602B

...

...

...

...

...

...

9 ⁄ 16

–27

or0.

5625

–27

UN

S2A

...

...

...

...

0.53

360.

0037

...

2B..

...

...

.0.

5432

0.00

48..

.

5 ⁄ 8–

14or

0.62

5–

14U

NS

2A..

...

...

...

...

...

.0.

5385

2B..

.0.

564

...

...

...

...

5 ⁄ 8–

27or

0.62

5–

27U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

3 ⁄ 4–

14or

0.75

0–

14U

NS

2A..

...

...

...

...

...

.0.

6635

2B..

...

...

...

...

...

.

3 ⁄ 4–

18or

0.75

0–

18U

NS

2A..

...

...

...

...

...

.0.

6825

2B..

...

...

...

...

...

.

3 ⁄ 4–

24or

0.75

0–

24U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

3 ⁄ 4–

27or

0.75

0–

27U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

7 ⁄ 8–

10or

0.87

5–

10U

NS

2A..

...

...

...

.0.

8022

0.00

600.

7542

2B..

...

...

.0.

8178

0.00

78..

.


175

Tabl

eE-

2Li

mit

sas

List

edin

Tabl

eD

-1(F

orm

erly

3B)P

rior

toAS

ME

B1.

1-20

03Ed

itio

n(C

ont’

d)

Exte

rnal

Inte

rnal

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

Func

tion

alD

iam

eter

Func

tion

alD

iam

eter

UN

RM

inor

Maj

orM

ajor

Dia

met

er[N

ote

(1)]

Min

orD

iam

eter

[Not

e(1

)]N

omin

alS

ize

and

Ser

ies

Dia

met

er,

Dia

met

er,

Thre

ads/

in.

Des

igna

tion

Clas

sA

llow

ance

Max

.M

in.

Max

.M

in.

Tole

ranc

eM

ax.

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

Tole

ranc

eM

in.

7 ⁄ 8–

18or

0.87

5–

18U

NS

2A..

...

...

...

.0.

8329

0.00

460.

8075

2B..

...

...

.0.

8449

0.00

60..

.

7 ⁄ 8–

24or

0.87

5–

24U

NS

2A..

...

...

...

.0.

8426

0.00

41..

.2B

...

...

...

0.85

320.

0052

...

7 ⁄ 8–

27or

0.87

5–

27U

NS

2A..

...

...

...

.0.

8458

0.00

39..

.2B

...

...

...

0.85

600.

0051

...

1–

10or

1.00

0–

10U

NS

2A..

...

...

...

...

...

.0.

8792

2B..

...

...

...

...

...

.

1–

18or

1.00

0–

18U

NS

2A..

...

...

...

...

...

.0.

9325

2B..

...

...

...

...

...

.

1–

24or

1.00

0–

24U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

1–

27or

1.00

0–

27U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

11 ⁄ 8–

10or

1.12

5–

10U

NS

2A0.

0018

1.12

321.

1103

1.05

821.

0520

...

1.00

422B

...

...

...

1.06

800.

0080

...

11 ⁄ 8–

14or

1.12

5–

14U

NS

2A..

...

...

...

...

...

.1.

0384

2B..

.1.

064

...

...

...

...

11 ⁄ 8–

24or

1.12

5–

24U

NS

2A..

...

...

...

.1.

0924

0.00

421.

0742

2B..

...

...

.1.

1034

0.00

55..

.

11 ⁄ 4–

10or

1.25

0–

10U

NS

2A..

...

...

...

...

...

.1.

1291

2B..

...

...

...

...

...

.

11 ⁄ 4–

14or

1.25

0–

14U

NS

2A..

...

...

...

...

...

.1.

1634

2B..

...

...

...

...

...

.

11 ⁄ 4–

24or

1.25

0–

24U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

13 ⁄ 8–

10or

1.37

5–

10U

NS

2A..

...

...

...

...

...

.1.

2541

2B..

...

...

...

...

...

.

13 ⁄ 8–

14or

1.37

5–

14U

NS

2A..

...

...

...

.1.

3216

0.00

541.

2884

2B..

.1.

314

...

1.33

560.

0070

...

13 ⁄ 8–

24or

1.37

5–

24U

NS

2A..

...

...

...

.1.

3423

0.00

43..

.2B

...

...

...

1.35

350.

0056

...

11 ⁄ 2–

10or

1.50

0–

10U

NS

2A..

...

...

...

...

...

.1.

3791

2B..

...

...

...

...

...

.

11 ⁄ 2–

14or

1.50

0–

14U

NS

2A..

...

...

...

...

...

.1.

4133

2B..

...

...

...

...

...

.

11 ⁄ 2–

24or

1.50

0–

24U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

15 ⁄ 8–

10or

1.62

5–

10U

NS

2A..

...

...

...

...

...

.1.

5041

2B..

...

...

...

...

...

.

15 ⁄ 8–

14or

1.62

5–

14U

NS

2A..

...

...

...

...

...

.1.

5383

2B..

.1.

564

...

...

...

...




176

Tabl

eE-

2Li

mit

sas

List

edin

Tabl

eD

-1(F

orm

erly

3B)P

rior

toAS

ME

B1.

1-20

03Ed

itio

n(C

ont’

d)

Exte

rnal

Inte

rnal

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

Func

tion

alD

iam

eter

Func

tion

alD

iam

eter

UN

RM

inor

Maj

orM

ajor

Dia

met

er[N

ote

(1)]

Min

orD

iam

eter

[Not

e(1

)]N

omin

alS

ize

and

Ser

ies

Dia

met

er,

Dia

met

er,

Thre

ads/

in.

Des

igna

tion

Clas

sA

llow

ance

Max

.M

in.

Max

.M

in.

Tole

ranc

eM

ax.

(Ref

.)Cl

ass

Min

.M

ax.

Min

.M

ax.

Tole

ranc

eM

in.

15 ⁄ 8–

24or

1.62

5–

24U

NS

2A..

...

...

...

.1.

5922

0.00

44..

.2B

...

...

...

...

...

...

13 ⁄ 4–

10or

1.75

0–

10U

NS

2A..

...

...

...

...

...

.1.

6291

2B..

...

...

...

...

...

.

13 ⁄ 4–

14or

1.75

0–

14U

NS

2A..

...

...

...

...

...

...

.2B

...

...

...

...

...

...

13 ⁄ 4–

18or

1.75

0–

18U

NS

2A..

...

...

...

...

...

.1.

6824

2B..

...

...

...

...

...

.

17 ⁄ 8–

10or

1.87

5–

10U

NS

2A0.

0019

1.87

311.

8602

1.80

811.

8016

...

1.75

342B

...

...

...

1.81

840.

0084

...

17 ⁄ 8–

14or

1.87

5–

14U

NS

2A..

...

...

...

...

...

.1.

7883

2B..

.1.

814

...

...

...

...

17 ⁄ 8–

18or

1.87

5–

18U

NS

2A..

...

...

...

...

...

.1.

8074

2B..

...

...

...

...

...

.

2–

10or

2.00

0–

10U

NS

2A..

...

...

...

...

...

.1.

8790

2B..

...

...

...

...

...

.

2–

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21 ⁄ 16

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1130

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2.15

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0052

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21 ⁄ 4–

10or

2.25

0–

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NS

2A..

...

...

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1765

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652.

1290

2B..

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1935

0.00

85..

.

21 ⁄ 4–

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2.25

0–

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NS

2A..

...

...

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.2.

1962

0.00

572.

1633

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2110

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.

21 ⁄ 4–

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2.25

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2.24

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2398

2.21

242.

2073

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512.

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2B..

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3108

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2702

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21 ⁄ 2–

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177

Tabl

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2Li

mit

sas

List

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Tabl

eD

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orm

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3B)P

rior

toAS

ME

B1.

1-20

03Ed

itio

n(C

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d)

Exte

rnal

Inte

rnal

Pitc

hD

iam

eter

and

Pitc

hD

iam

eter

and

Func

tion

alD

iam

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Func

tion

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eter

UN

RM

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orM

ajor

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ote

(1)]

Min

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[Not

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.)Cl

ass

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21 ⁄ 2–

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.

23 ⁄ 4–

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178

Tabl

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2Li

mit

sas

List

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Tabl

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-1(F

orm

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3B)P

rior

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ME

B1.

1-20

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itio

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hD

iam

eter

and

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hD

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tion

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iam

eter

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tion

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ote

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GEN

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The

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for

Func

tion

alD

iam

eter

.


OTHER STANDARDS FOR SCREW THREADS

Unified Inch Screw Threads (UN and UNR Thread Form). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.1-2003Gages and Gaging for Unified Inch Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.2-1983 (R2001)Screw Thread Gaging Systems for Dimensional Acceptability —

Inch and Metric Screw Threads (UN, UNR, UNJ, M, and MJ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.3M-1992 (R2001)Acme Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.5-1997Nomenclature, Definitions, and Letter Symbols for Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.7M-1984 (R2001)Stub Acme Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.8-1988 (R2001)Buttress Inch Screw Threads 7°/45° Form With 0.6 Pitch Basic Height of Thread Engagement . . . . . . . . . . . . . . . . . . . . . . . B1.9-1973 (R2001)Unified Miniature Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.10M-2004Microscope Objective Thread . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.11-1958 (R2001)Class 5 Interference-Fit Thread . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B1.12-1987t(R1998)Metric Screw Threads — M Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.13M-2001Unified Inch Screw Threads (UNJ Thread Form) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.15-1995Gages and Gaging for Metric M Screw Threads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.16M-1984 (R2001)Pipe Threads, General Purpose (Inch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.20.1-1983 (R2001)Dryseal Pipe Threads (Inch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.20.3-1976 (R1998)Gaging for Dryseal Pipe Threads (Inch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.20.5-1991 (R1998)Hose Coupling Screw Threads (Inch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.20.7-1991 (R1998)Metric Screw Threads: MJ Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.21M-1997Gages and Gaging for MJ Series Metric Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.22M-1985 (R2001)Screw Threads — Standard Practice for Calculating and Rounding Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1.30-2002

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ASME B1.1-2003

M02803



AN AMERICAN NATIONAL STANDARD

Documents

Transcript of AN AMERICAN NATIONAL STANDARD