BRITISH STANDARD BS 7419:1991

Specification for

Holding down bolts

BS 7419:1991

This British Standard, having been prepared under the direction of the General Mechanical Engineering Standards Policy Committee, was published under the authority of the Standards Board and comesinto effect on29 March 1991

© BSI 12-1999

The following BSI references relate to the work on this standard:Committee reference GME/9Draft for comment 90/75944 DC

ISBN 0 580 19403 5

Committees responsible for this British Standard

The preparation of this British Standard was entrusted by the General Mechanical Engineering Standards Policy Committee (GME/-) to Technical Committee GME/9, upon which the following bodies were represented:

BEAMA LtdBritish Constructional Steelwork Association LtdBritish Industrial Fasteners FederationBritish Railways BoardBritish Steel IndustryBritish Steel Industry (Wire Section)Gauge and Tool Makers’ AssociationMinistry of DefenceSociety of Motor Manufacturers and Traders LimitedWasher Manufacturers’ Association of Great Britain

The following body was also represented in the drafting of the standard, through subcommittees and panels:

Steel Construction Institute

Amendments issued since publication

Amd. No. Date Comments

BS 7419:1991

© BSI 12-1999 i

Contents

PageCommittees responsible Inside front coverForeword ii1 Scope 12 Dimensions 13 Characteristics 64 Complete designation for the purpose of an enquiry or order 6Figure 1 — Dimensions of square head bolts 3Figure 2 — Dimensions of hexagon head bolts 5Table 1 — Dimensions of square head bolts 2Table 2 — Dimensions of hexagon head bolts 4Table 3 — Tolerance on nominal length 6Table 4 — Preferred sizes 6Table 5 — Characteristics 6Publication(s) referred to Inside back cover

BS 7419:1991

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Foreword

This British Standard has been prepared under the authority of the General Mechanical Engineering Standards Policy Committee to provide a metric series standard for holding down bolts.A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application.

Compliance with a British Standard does not of itself confer immunity from legal obligations.

Summary of pagesThis document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 6, an inside back cover and a back cover.This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.

BS 7419:1991

© BSI 12-1999 1

1 ScopeThis British Standard specifies the general dimensions, tolerances, materials and mechanical properties for holding down bolts of product grade C for use in connecting steel structures to their foundations and in similar applications.Bolts with square heads and square necks are specified. Two possible forms of square neck are covered.Bolts with hexagon heads are also specified.Other forms of holding down bolts are not covered.NOTE The titles of the publications referred to in this standard are listed on the inside back cover.

2 DimensionsThe general dimensions and tolerances of holding down bolts with square heads and square necks shall be as given in Table 1 and Table 3, andFigure 1.The dimensions and tolerances of holding down bolts with hexagon heads shall be as given inTable 2 and Table 3, and Figure 2.NOTE 1 Preferred sizes for square and hexagon head holding down bolts are listed in Table 4.NOTE 2 Symbols and descriptions of dimensions may be found in BS 6565. The symbol v is the dimension across flats of the underhead square neck.

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Table 1 — Dimensions of square head bolts

Thread (d) M16 M20 M24 M30 M36 M42 M48 M56 M64P (pitch) 2 2.5 3 3.5 4 4.5 5 5.5 6

b max. 122 127.5 133 140.5 148 155.5 163 172.5 182

min. 116 120 124 130 136 142 148 156 164

ds max. 16.7 20.84 24.84 30.84 37 43 49 57.2 65.2

min. 15.3 19.16 23.16 29.16 35 41 47 54.8 62.8

k nom. 10 12.5 15 18.7 22.5 26 30 35 40

min. 9.25 11.6 14.1 17.65 21.45 24.95 28.95 33.75 38.75

max. 10.75 13.4 15.9 19.75 23.55 27.05 31.05 36.25 41.25

r min. 0.6 0.8 0.8 1 1 1.2 1.6 2 2

s nom. = max. 24 30 36 46 55 65 75 85 95

min. 23.16 29.16 35 45 53.8 63.1 73.1 82.8 92.8

f nom. 8 10 12 15 18 21 24 28 32

min. 7.25 9.25 11.1 14.1 17.1 19.95 22.95 26.95 30.75

max. 8.75 10.75 12.9 15.9 18.9 22.05 25.05 29.05 33.25

v max. 16.7 20.84 24.84 30.84 37 43 49 57.2 65.2

min. 15.3 19.16 23.16 29.16 35 41 47 54.8 62.8

x max. 5 6.3 7.5 9 10 11 12.5 14 15NOTE Dimensions are in millimetres.

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1) Incomplete threads, u k 2p.

Figure 1 — Dimensions of square head bolts

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Table 2 — Dimensions of hexagon head bolts

Thread (d) M16 M20 M24 M30 M36 M42 M48 M56 M64P (pitch) 2 2.5 3 3.5 4 4.5 5 5.5 6

b max. 122 127.5 133 140.5 148 155.5 163 172.5 182

min. 116 120 124 130 136 142 148 156 164

c max. 0.8 0.8 0.8 0.8 0.8 1 1 1 1

da max. 18.7 24.4 28.4 35.4 42.4 48.6 56.6 67 75

ds max. 16.7 20.84 24.84 30.84 37 43 49 57.2 65.2

min. 15.3 19.16 23.16 29.16 35 41 47 54.8 62.8

dw min. 22 27.7 33.25 42.75 51.11 59.95 69.45 78.66 88.16

e min. 26.17 32.95 39.55 50.85 60.79 71.3 82.6 93.56 104.86

k nom. 10 12.5 15 18.7 22.5 26 30 35 40

min. 9.25 11.6 14.1 17.65 21.45 24.95 28.95 33.75 38.75

max. 10.75 13.4 15.9 19.75 23.55 27.05 31.05 36.25 41.25

r min. 0.6 0.8 0.8 1 1 1.2 1.6 2 2

s nom. = max. 24 30 36 46 55 65 75 85 95

min. 23.16 29.16 35 45 53.8 63.1 73.1 82.8 92.8

x max. 5 6.3 7.5 9 10 11 12.5 14 15NOTE Dimensions are in millimetres.

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1) Incomplete threads, u k 2p.Dimension is in millimetres.

Figure 2 — Dimensions of hexagon head bolts

BS 7419:1991

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Table 3 — Tolerance on nominal length l

Table 4 — Preferred sizes

3 CharacteristicsMaterials, tolerances, mechanical properties and associated nuts for holding down bolts shall be as given in Table 5.

4 Complete designation for the purpose of an enquiry or orderWhen designating for the purpose of an enquiry or order, the following information shall be given:

a) general product description, i.e. Holding down bolts;b) head form, i.e. Square square, or Hexagon;c) the letter “M” indicating that the product is ISO metric;d) the nominal size (thread diameter) of the product in millimetres;e) the nominal length in millimetres;f) the strength grade;g) the number of this British Standard, i.e. BS 7419;h) details of the associated nut in accordance with the appropriate British Standard, i.e. BS 4190, BS 3962 or BS 4395-1;i) details of the coating (if required), in accordance with the appropriate British Standard (e.g. BS 729, BS 1706, BS 4921).

Examples:Square head holding down bolts 20 mm in diameter, 450 mm long, strength grade 4.6 with nuts to BS 4190 would be designated:

1) Holding down bolts, Square squareM20 × 450, 4.6 to BS 7419, nuts to BS 4190.

Hexagon head pre-loaded holding down bolts 24 mm in diameter, 600 mm long, strength grade 8.8, nuts to BS 4395-1, galvanized would be designated:

2) Pre-loaded holding down bolts, Hexagon M24 × 600, 8.8 to BS 7419, nuts to BS 4395-1, galvanized to BS 729.

Table 5 — Characteristics

Nominal length Tolerance

mm mm

250 k l k 315 ± 5.20315 < l k 400 ± 5.70400 < l k 500 ± 6.30500 < l k 625 ± 6.80625 < l k 800 ± 7.20800 < l k 1 000 ± 7.40

1 000 < l k 1 250 ± 7.60

Nominal length l for thread (d):M16 M20 M24 M30 M36

mm mm mm mm mm

300 300 — — —375 375 375 — —450 450 450 450 450525 525 525 525 525600 600 600 600 600— 750 750 750 750— 1 000 1 000 1 000 1 000— — 1 250 1 250 1 250

Material Steel

Thread tolerance 8g (see BS 3643-1 and BS 3643-2)Mechanical property classa d k 39 mm: 4.6, 8.82) (see BS 6104-1)

d > 39 mm: as agreedTolerance (for product grade C) See BS 6322-1Finish a) as processed

b) galvanized to BS 1706c) sherardized to BS 4921d) electroplated to BS 1706

Acceptability For acceptance procedure, see BS 6587Associated nutsb See BS 4190 or BS 3692a The designation symbol for the property classes according to BS 6104-1 can also be used for thread sizes above M39, provided that the finished product has all the properties assigned to the designation symbols in BS 6104-1.b When bolts of property class 8.8 are to be preloaded, nuts and hardened washers in accordance with BS 4395-1 should be specified.

BS 7419:1991

© BSI 12-1999

Publication(s) referred to

BS 729, Specification for hot dip galvanized coatings on iron and steel articles. BS 1706, Method for specifying electroplated coatings of zinc and cadmium on iron and steel. BS 3643, ISO metric screw threads. BS 3643-1, Principles and basic data. BS 3643-2, Specification for selected limits of size. BS 3692, Specification for ISO metric precision hexagon bolts, screws and nuts. Metric units. BS 4190, Specification for ISO metric black hexagon bolts, screws and nuts. BS 4395, Specification for high strength friction grip bolts and associated nuts and washers for structural engineering. BS 4395-1, General grade. BS 4921, Specification for sherardized coatings on iron or steel. BS 6104, Mechanical properties of fasteners. BS 6104-1, Specification for bolts, screws and studs. BS 6322, Tolerances for fasteners. BS 6322-1, Specification for tolerances for bolts, screws and nuts with thread diameters U 1.6 mm and k 150 mm and product grades A, B and C. BS 6565, Method for dimensioning and designating bolts, screws, studs and nuts. BS 6587, Method of acceptance inspection for fasteners.

BS 7419:1991

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