BRITISH STANDARD 46 : Part 1 : 1958

CONFIRMED OCTOBER 1985

KEYS AND K E Y W A Y S

@ Printed by Official BSI Distributor - Index House Ascot SL5 7EU UK S +44 (0)1344 874343 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW

BRITISH STANDARD SPECIFICATION

KEYS AND

K E Y W A Y S

B.S. 46 : Part 1 : 1958 Incorporating amendments issued May 1959 (PD 3375), January 1%1 (PD 4022)

and January 1964 (PD 5124)

CONFIRMED OCTOBER 1985

B R I T I S H S T A N D A R D S I N S T I T U T I O N lncorporated by Royal Charter

2 PARK STREET, LONDON, W IA 2BS

Telex: 266333 Telephone: 071-629 9000

UDC 621.886.8

. .

B.S. 46 : Part 1 : 1958

THIS BRITISH STANDARD, having been approved by the Mechanical Engineering Industry Standards Committee and endorsed by the Chairman of the Engineering Divisional Council, was published under the authority of the General Council on 30th May, 1958.

First published (as B.S. 46), September, 1909. First revision (as B.S. 46, Part l) , October, 1924. Second revision, April, 1929. Third revision, February, 1953. Fourth revision, May. 1958.

The Institution desires to call attention to the fact that this British Standard does not purport to include all the necessary provisions of a contract.

In Order to keep abreast of Progress in the industries concerned, British Standards are subject to periodical review. Suggestions for improvements will be recorded and in due Course brought to the notice of the committees charged with the revision of the Standards to which they refer.

A complete list of British Standards, numbering over 9,000, fully indexed and with a note of the contents of each, will be found in the BSI Catalogue which may be purchased from BSI Sales Department. The Catalogue may be consulted in many public libraries and similar institutions. This Standard makes reference to the following British Standards : B.S. 308. Engineering drawing practice. B.S. 350. Conversion factors and tables. B.S. 970. Wrought steels. B.S. 1916. Limits and fits for engineering.

British Standards are revised, when necessary, by the issue either of amendment Slips or of revised editions. It is important that Users of British Standards should ascertain that they are in possession of the latest amenainents or editions.

The following B.S.I. references relate to the work on this Standard :- Committee referenus, MEE/4. MEE/4/4 Draft Tor cornrnent CX(MEE) 6855

2

B.S. 46 : Part 1 : 1958

CO-OPERATING ORGAMZATIONS

The Mechanical Engineering Industry Standards Committee, under whose supervision this British Standard was prepared. consists of representatives from the following Government departments and scientific and industrial organizations :-

Air Ministry Associated Officers' Technical Committee Association of Consulting Engineers (Incorporated) British Chemical Plant Manufacturers' Association British Compressed Air Society

*Admiralty

*British Electrical and Allied Manufacturers' Association *British Engineers' Association *British Gear Manufacturers' Association *British Internal Combustion Engine Manufacturers' Association *British Iron and Steel Federation British Railways, The British Transport Commission Crown Agents for Oversea Governments and Administrations

Electricity Council, the Generating Board and Area Boards *D.S.I.R.-Mechanical Engineering Research Laboratory

in England and Wales *Engineering Equipment Users' Association

*High Commission of India Gas Council

Institdte of Marine Engineers Institute of Petroleum Institution of Civil Engineers Institution of Gas Engineen InstitJtion of Heating and Ventilating Engineers

Institution of Mechanical Engineers (Automobile Division) *Institution of Mechanical Engineers

*Institution of Production Engineers *Locomotive and Allied Manufacturers' Association of Great Britain

Machine Tool Trades Association Ministry of Labour and National Service (Factory Inspectorate) Ministry of Power

*Ministry of Supply Ministry of Trcnsport and Civil Aviation Ministry of Works National Coal Board National Physical Laboratory (D.S.I.R.) Radio Industry Council War Office

The organizations marked with an asterisk in the above list. together with the following. were directly represented on the Committee entrusted with the preparation of this Standard :- Association of Crane Makers Bright Steel Bar Association British Cycle and Motor Cycle Industries' Association British Internal Combustion Engine Research Association British Shipbuilding Research Association Gauge and Tool Makers' Association Institution of Engineers and Shipbuilders in Scotland Keyrnakers' Association Milling Cutter and Reamer Association North East Coast Institution of Engineen and Shipbuilders Society of British Aircraft Constructon Steelworks Plant Association Tapcr Pin Manufacturers' Association

3

B.S. 46 : Part 1 : 1958

CONTENTS

Co-Operating organizations

Foreword

1.

2.

3.

4.

5.

6.

7.

SPECIFICATION

Page

3

6

S O P e 7 Materials 8

The application of keys and keyways a. Parallel keys 8 b. Taper keys 8 C. Tangential keys 9 d. Woodruff keys 9

Dimensions and tolerancea of parallel and taper keys and keyways 9

Dimensions and toleranw of Woodruff keys and keyways 10

Dimensions of tangential keys and keyways 24

Dimensions of keys and keyways for marine tailshafts 26

8. Keys and keyways for tapcrcd shaft ends 28

TAB=

1. Rectangular parallel keys, keyways and keybars 12

2. Square parallel keys, keyways and keybars 14

3. Rectangular tapcr keys and keyways, gib-hcad or plain 16

4. Square taper keys and keyways, gib-head or plain 18

20 5. Woodruff keys and keyways

6. Comparison of Woodruf key numbers (Whitney, British and Amrican) 22

4

0

0

0

0

B.S. 46 : Part 1 : 1958

TABLES-ontinued. Page

7. Tangential keys 25

8. Rectangular parallel keys for marine tailshafts 26

9. Preferred lengths of plain keys, rectangular or square section, parallel or taper 30

10. Preferred lengths of gib-head keys rectangular or square section 31

APPENDICES

A. Preferred lengths of keys 29

B. Approximate equivalents of metric and inch units 32

5

B.$. 46 : Part 1 : 1958

BRITISH STANDARD FOR

KEYS AND KEYWAYS

FOREWORD

The standardization of keys and keyways was first considered by the Engineering Standards Committee (the original name and form of the present B.S.I.). As a result Standard Specification No. 46, dealing only with rectangular parallel keys, keybars and keyways, was published in 1909.

In subsequent revisions, other types of keys were added to the Standard and Parts 2 and 3 of B.S. 46 were prepared for parallel splines and taper pins respectively. Parts 2 and 3 have since been further revised and Part 2 has been published as B.S. 2059.

This revision of B.S. 46, Part 1 for Keys and keyways has been prepared under the authority of 7he Mechanical Engineering Industry Standards Committee in response to requests for larger manufacturing tolerances. The various types of keys and keyways now have consistent dimensions and tolerances for each size as b r as possible, and this will enable a Standard range of Cutters to be used for the machining of the various types of keyways. The increased tolerances recommended in this Standard may entail more fitting of keys into keyways than was envisaged in the 1953 edition. This is inevitable with an increase in tolerance on the keys and keyways. Careful consideration has been given to various requests for increases in tolerances and also for decreases in tolerances but the Committee have come to the conclusion that the tolersnces now given are those most acceptable to industry at the present time.

The Committee responsible for this revision of B.S. 46, Part 1, gave earnest consideration to the specification of limits and fits to B.S. 1916 for the keys and keyways specified. It was decided not to introduce these limits and fits as the key and keyway Standard does not represent finished articles for prescribed conditions of assembly. It recommends dimensions and tolerances from which required fits can be obtained by fitting to meet most design requirements. The Committee was influenced in reaching this decision by the absence of a Standard range of Cutters for machining to B.S. 1916 and the non-availability of keybar to these limits at the time the revision of this Standard was being prepared. This decision will be reviewed in the light of circumstances existing when further revision is contemplated.

The principle of the dimensions and tolerances recommended is to provide for each key to be retained in the shaft rather more securely than in the mating hub but this can be varied to meet Special applications within the dimensional limits recommended in this Standard.

6

0

B.S. 46 : Part 1 : 1958

The tables of preferred key lengths given in Appendix A have been revised to conform with present-day requirements and the key sizes have been brought into accord with tables 1, 2, 3 and 4.

Whilst the details of radii and charnfers are not a mandatory Part of this specification the recomrnendations shown are in graduated steps of nominal value instead of by formulae, as with the forrnulae of former issues a Special Cutter radius was required for each size of keyway. Each radius recomrnended now applies to a range of keyway sizes.

Owing to the difficulties of obtaining keybar in thirty-seconds of inch, keys formerly of these sizes have been replaced by those which are more readily available. Minor changes in the range of shaft sizes have been made to accornmodate this.

The revised table for -keys and keyways for marine tailshafts has been compiled by the British Shipbuilding Research Association from a survey of thc current practice of British shipbuilding and marine engineering firms and frorn theoretical and experimental studies.

Thc table of Woodruff keys and keyways has been extended into the range of snlaller sizes to rneet requirements for instrument and similar purposes. To facilitate the changeover to the recomrnended Woodruff key designation as shown in Table 5 , the obsolete key and Cutter nurnbers have been given in Table 6.

The notes relating to keys and keyways for tapered shaft ends have been retained unaltered.

A requirement has been stated for tangential keys and the Type A tangential key of the 1929 issue of B.S. 46 has been reinserted in this revision.

SPECIFICATION

SCOPE

1. This British Standard relates to the following : n. Rectangular parallel keys and keyways. b. Square parallel keys and keyways. C. Rectangular taper keys and keyways, piain and gib-head. (1. Square taper keys and keyways, plain and gib-head. e. Woodruff keys and keyways. f : Tangential keys and keyways. ,L'. Keys and keyways for marine tailshafts. 11. Keys and keyways for tapered shaft ends. Decimal values in the tables have been rounded off to three significant

figures. NOTE. This specification is based on British units. For the convenience of users approxirnate equivalents in metric units are given in Appendix B. More accurate conversions should he obtained from the tables in B.S. 350 ' Conversion factors and tablcs.'

7

B.S. 46 : Part 1 : 1958

MATERIALS

2. a. Keys and keybar complying with Tables 1 to 7 of this British Standard shall be manufactured from steel to En 6A, En 8 or En 9 of B.S. 970, ' Wrought Steels,' and those complying with Table 8 from steel to En 4 or En 5. It is recommended that En 6A and En 8 steels should be cold drawn for keys in sections up to 2 in. square and hot rolled (En 8 in

/UR.. condition NGC 1 (Normalized)) for larger sections, and that En 9 steek should not be cold drawn for keys of sections larger than % in. Square.

b. Bright keybar is not normally available in sections over 1 % in.

AI altered

I964

THE APPLICATION OP KEYS AND KEYWAYS

3. As it is not possible to foresee the combination of design considerations for any given application, the selection of the proper type of key must rest with the design authority. The following are general recommenda- tions for use when circumstances permit and when keying is preferred to other methods of transmitting torque (e.g. splines).

U. Purullel keys. For use for transmitting unidirectional torques on transmissions not subject to heavy starti,.g loads and where periodic withdrawal or sliding of the hub memkr may be required. In many instanccs, particularly couplings, a gib-head cannot be accommodated, and therc is insufficient room to drift out the key from behind. In these c8sts it is necessary to withdraw the component over the key and a parallel key is essential. Parallel square and rcctangular keys are normally side fitting with top clearance and are usually retained in the shaft rather more securely than in the hub.

(i) Rectungulur. The general purpost key for shafts greater than 1 in. diametcr.

(ii) Sqwe. For use with shafts up to and including 1 in. diameter or for shafts up to 6 in. diamcter where it is desirable to have a greater key depth than is provided by rectangular keys.

M I In cases of stepped shafts the larger diameters an usually required

3 by considerations other than torque e.g. resistancc to bending. Where components such as fans, gears, impcllers etc., are attached to thc larger shaft diameter, the usc of a key der than Standard for that diametcr may bc permissible. As this results in unqual disposition of the key in the shaft and its related hub the dimcnsions H and h must be re- calculated to maintain thc T/2 relationship.

b. Tuper keys. For transmitting hcavy unidirectional, rcversing or vibrating torques and in applications where periodic withdrawal of the key may bc a nccessity.

For transmitting unidircctional torquts taper keys arc top fitting. but may be top and side fitting wkre rcquircd.

For transmitting rcversing or vibratory torques taper keys may be top

8

B.S. 46 : Part 1 : 1958

and side fitting where required. In this case the keyway in the hub should have the Same width value as the keyway in the shaft (Le., Columns 8 and 9 of Tables 3 and 4).

Taper keys cannot be used in applications requiring a sliding hub member.

(i) Recrangular und Square. Taper keys of rectangular section are for general purposes and are of less depth than square keys.

Taper keys of square section are for use with shafts up to and including 1 in. diameter or for shafts up to 6 in. diameter where it is desirable to have greater key depth.

(ii) Gib-hend. Gib-heads are provided to facilitate the withdrawal of keys.

(iii) Pluirr. Where little or no protuberance is permissible.

C. Tangential ~ P Y S . For the transmission of reversing torque, usually under conditions of heavy loading.

d. Woodruj' keys. For light applications, or angular location of associated parts on tapered shaft ends.

These keys are not recommended for other applications, but if so used Corner radii in the shaft and hub keyways are advisable to reduce stress concentration.

DIMENSIONS AND TOLERANCES OF PARALLEL AND TAPER KEYS AND KEYWAYS

4. The dimensions and tolerances for key and keyway widths given in Tables I , 2, 3 and 4 are based on the width of the key W and provide a fitting allowance. The fitting allowance is designed to permit an inter- ference between the key and the shaft keyway and a slightly easier condition between the key and the hub keyway.

The maxirnum and minimum values in Tables 1, 2, 3 and 4 are based 011 the following :

Width of key and keybar, W = Nominal size with a plus tolerance. Width of keyway in shaft, W, = Nominal size with a minus tolerance. Width of keyway in hub, W h = Nominal size with a plus tolerance. Minimum width of key = Maximum width of keyway in shaft.

a. Parallel keys und keyways. (i) The dimensions and tolerances for side-fitting keys of rectangular parallel section. and for the appropriate keybar and keyways shall be as given in Table 1.

(ii) The dimensions and tolerances for side-fitting keys of square parallel section and for the appropriate keybar and keyways shall be as given in Table 2.

b. Taper keys und keywap. (i) The dimensions and tolerances for taper keys of rectangular section with or without gib-heads shall be as given in Table 3. (See also Clause 36).

9

B.S. 46 : Part 1 : 1958

(ii) The dimensions and tolerances for taper keys of square section with or without gib-heads shall be as given in Table 4. (See also Clause 3h).

(iii) The basic taper for all taper keys and keyways in hubs shall be 1 in 100.

C. DeptJz o f k e y w u p . The depth of the keyway shall be obtained by measuring from the circumference of the shaft diametrically opposite, or from the bore of the hub to the root of the keyway along the centre line diametrically opposite and shall not be measured from the side Corner. The method of dimensioning keyways in shafts and hubs on drawings should conform to the recommendations of B.S. 308, ' Engineering drawing practice.' To obtain the dimensions for recording on the drawing, the keyway depths and tolerances shall be applied to the basic shaft diameter.

d. Radii und chanrfers. Corner radii are recommended for keyways, as Stress concentration in Corners may lead to failure. Keys and keybar are not normally chamfered or radiused in the condition as supplied, but this may be done at the time of fitting. or, by arrangement between the purchaser and the manufacturer, during manufacture.

Radii and chamfers are shown as nominal values in columns of Tables 1,2,3 and 4. The chamfer on the key should in each case be of the minimum value to clear the actual radius in the keyway. NOTE. In the case of shrink and heavy force fits i t may be found necessary to depart from the width and depth tolerances laid down for keys and keyways.

Any Variation in the width of keyway rnust be such that the greatest width is at the end from which the key enters.

Any Variation in the depth of keyway rnust be such that the greatest depth is at the end from which the key enters.

Any Variation in the thickness of the key must be such that the greatest thickness U at the end from which the key is driven.

This specification d e s not take account of misalignment and or ofiset greater than that provided for in the size tolerance. in the case of shrink and heavy force fits, true alignment must be ensured.

DIMENSIONS AND TOLERANCES OP WOODRUFF KEYS AND KEYWAYS

5. The dimensions and limits of tolerances for British Standard Woodruff keys and keyways shall be as shown in Table 5. Provision is made in 0 Table 5 for an optional alternative design of WoodrufF key which difTers from the normal form in its depth as shown at H in the Sketch and Table.

a. The designation of Woodruf key numbers. The following system is applied to Woodruff keys and Woodruff key Cutters. The British and American designations are identical. Each key is designated by three or more significant digits. The last two digits give the nominal diameter in eighths of an inch. The digit or digits preceding the last two give the nominal width (thickness) in thirty-seconds of an inch

10

B.S. 46 : Part 1 : 1958

Thus No. 204 refers to a key z i ~ X ','a in., or 1 6 in. thick X 4/2 in. diameter, similarly, 1210 refers to a key ' % 2 X " ' 8 in., or ?6 in. thick X 1% in. diameter.

b. Depth of keywuy. The depth of a Woodruif keyway shall be measured along the centre line from the peripherv of the shaft, or the circumference of the hub bore, to the root of the keyway. The depth of the keyway in a tapered shaft shali be measured normal to the shaft surface. (This is illustrated in B.S. 308, ' Engineering drawing practice ').

NOTE ON KEYS FOR LARGER SHAFTS AE The sizes of shafts shown in Tables 1, 2, 3 and 4 of this Standard are those for

which the respective types of keys are considered to be normally appropriate. For 1964 larger shafts, it is considered that tangential keys, multiple keys or splines would be rnore appropriate.

However. if it is decided to use Single parallel keys on shafts larger than those considered normal for such keys in this Standard, the following formulae niay be applied to establish (nominal) values related to the shaft diameter ' d '. (For the purposes of the tables, ' d ' is the diarneter of the largest shaft for each key size i.e. ' d ' corresponds to column 2 of the tables. For intermediate shaft diameters or shaft diarneters larger than those of the tables, H should, of Course. be calculated frorn (iii), using for ' d * the nominal shaft diameter.)

(i) Key width W = - d 4 (ii) Key thickness T = g f o r Tables 1 and 3

or = T for Tables 2 and 4

d

d

(In Tables 1 and 3, T has in some sizes been rounded off to maintain the

T d W' inch fractional sizes.)

(iii) Keyway depth in shaft H =T +T - 4: - (iv) For parallel keys, keyway depth in hub h = (T - H) + X

where X is a clearance such that X min. = H min. + h min. - T max. X max. = H max. $- h max. - T min.

The incremental Pattern by which the tolerances (and clearance X) increase with shaft size may be Seen from an inspection of the tables, but it should be noted that a Point will be reached at which any further increase in tolerance (with increase in shaft size) would be neither necessary in manufacture nor acceptable in use.

11

Over

TABU 1. RECTANGULAR PARALLEL KEYS, KEYWAYS AND KEYBARS

i

1 1% 1%

I

i?

2 % ' 3

3 3% 4

5 6 7

8 9

n W 10

11 12 13

14 15 16

17 18 19 -

3% 4 5

6 7 8

9 10 11

12 13 14

15 16 17

18 19 20

0

0-502 0.500 0.627 0.625 0.752 0.750

0.877 0.875 1.003 1.000 1.253 1-250

1.504 1.500 1.754 1-750 2,005 2.000

2.255 2.250 2.505 2.500 2.755 2.750

3.006 3.000 3.256 3.250 3.506 3.500

3.756 3.750 4.008 4.000 4.258 4.250

4.508 4.500 4.758 4.750 5.008 5-000

.- -. -. -. - - I

0.315 0.312 0.441 0.438 0.503 0.500

i 0.629 10.625 0.754 0.750 0.879 0.875

1.006 1.000 1.256 1.250 1.381 1.375

1.506 1.500 1.631 1.625 1.881 1.875

2.008 2.000 2.133 2.125 2.383 2.375

2.508 2.500 2.633 2.625 2-883 2.875

0

I

0.499 ~ 0.500 i 0.190 0.624 j 0.625 1 0.260 0.749 I 0*750,0.299

!

0.874 0-875 i 0-370 0.999 ! 1-ooO 0,441 1.248 0-518 1.250

1.498

0.818 2.000 1.998 0.740 1.750 1.748 0-599 1.500

2.248

1.114 2.750 2.748 0.975 2.500 2.498 0.897 2-250

2.998

1.413 3.500 3.498 1.273 3.250 3.248 1.195 3.000

3.748

1.711 4.250 4.248 1.571 4.000 3.998 1,492 3-750

4.498

2.010 5.000 4.998 1 1.868 4.750 4.748 1.791 4.500

'NOTE. The koy chunfer thall be the minimum to cleu the keywry ndius.

oddrd Aa For largor shafts see the note following Clruse 5. J a . , J P M

0.196 ' 0.500 1 0.501 0.266 i 0.625 ~ 0.626 0.305 ! 0.750 j 0.751

0.376 ' 0.875 I 0.876 0.447 1 1.00~ i 1-001 0.524 1.250 1 1.252 0.605 1.m 1-502 0.746 1.750 1.752 0-824 2.000 2-002

I

'

0.905 2.250 2.252 0.983 2-500 2.502 1.122 2.750 2.752

1.203 3*000 3.002 1.281 3.250 3.252 1.421 3-5001 3.502

1-502 ~

3-750 1 3.752 1.581 I 4.000 1 4.002 1.721 1 4.250, 4.252 1.801 4.500 4.502 1.878 4.750 4.752 2.020 5.000 1 5.002

.. . .. .

0.131 10.137 0.185 j 0.191 0.209 ~ 0.215

0.264 0-270 ~

0-318 1 0.324 0.366 0-372

0.412 0.418 0.526 0.532 0.573 0.579

0.619 0 627 0-666 0-674 0.777 0.785

0.823 0.831 0.870 0.878 0.980 0.988

i 1.0261 1.036

1.229 1 1.239 1.277 1 1.287 1.385 1.395

I i Nomlnrl values ~ f c given.

0.020 0.020 Oa20

0-062 0.062 0.062

0.062 0.125 0.125

0.125 0.187 0.187

0.187 0-187 0.250

0.250 0.250 0.312

0.312

0.312 1 0.312 i I

.~

0.502 0-627 0.752

D.877 1.003 1.253

. . .

0.500 ! 0.315 0.625 0.441 0 750 ~ 0.503

0.875 0.629 1.OOO ~ 0.754 1.250 ! 0-879

0.312 0.438 0.500

0-625 0.750 0.875

1400 ~.

Bright keybar is not normally available in sections larger than the above.

W V, %: ..

-2 a L .. L

OL

L P

TABLE 2. SQUARE PARALLEL KEYS, KEYWAYS AND KEYBARS

t

All dlmensions are in inchts

i- 3 6 ~ 7 1 8 ' 9 !

Keyway h shaft

Ilf ~. -~ -.

Width W aad

Thickwss T

Diameter of Shaft Keyway in hub , ~ I ; Bright keybar __ ' Nominal ~ - Key size I - - I Width

WS Depth

H u p to and

ncluding

--

?4 ?4 1

1% 1% 1%

2 2% 3

3% 4 5

6 -

Over I. _ _ - Min. __

0.125 0.188 0.250

0.312 0.375 0.438

0-500 0.625 0.750

0.875 1.OOO 1.250

__-~

Max. - 0.127 0.190 0.252

0.314 0.377 0.440

0.502 0.627 0.752

0.877 1.003 1.253

1.504 -

_ _ _ Min. -

0.125 0.188 0.250

0.312 0.375 0.438

0.500 0.625 0-750

0.875 1.OoO 1-250

1.500 -

..

Min.

0.072 0.107 0.142

0.177 0.213 0.248

0.283 0.354

W xT Max. __

0.125 0.188 0.250

0-312 0.375 0.438

0.500 0.625

Min. .. . -. -

0-124 0.187 0.249

0.311 0-374 0.437

0.499 0.624 0-749

0-874 0.999 1.248

hlin.

0.125 0.188 0.250

0.312

Max.

0.078 0.113 0.148

0.183 0.219 0.254

0.289 0.360 0.430

0.501 0.572 0.713

0.854 -

Max. __-

0-126 0.189 0.251

0.313 0.376 0.439

0501 0.626 0.751

0876 1.001 1.252

1.502 -

0.115

0.142 0.169 0-197

0.224 0.278 0.333

0.387 0.442 0.551

0.661 -

0.175 1 0.010 ' 0.377 0.375 0.203 ~ 0.020 , 0.440 0.438

I I

'

0.230 I ~ 0.020 0.502 0.500

0.284 0.339

0-393 0.448 0.557

0.667 -

0.020 0.020

0.062 0.062 0.062

0.627 0.625 0.752 ~ 0.750 0.750 ~ 0.424

0.875 0-495 1.OOO 0-566 1.250 0.707

1.500 0.848 1*500 1 1.498 .. W Q) ul e

B.S.46 : Part 1 : 1958

tA-tD! TABLE 3. RECTANGULAR TAPER KEYS 0 , I L" 1

f

1 Basic, t ape r I in 100 on th is f a c e t

T i

Gib-head key

Section at deep end of keyway in hub

3

Key size

All dimensions

Max. ~ Min.

0.314 0-312 0.377 0.375 0.440 0.438 0.502 0.500 0.627 0.625 0-752 0.750

~ - .~ ~~ Max. : Min.

0.254 0.249 0.254 0.249 0.316 ' 0.311 0.316 0.311 0.442 0.437 0.504 0.499

~~

3 ~ 3% ' 7/e Y 5/8 0.877 0.875 ' 0.630 0-624 3% 4 , 1 X % 1.003 1-OOO ' 0755 0 749 4 5 1% X 7/a 1.253 1.250 0.880 0.874 5 6 1% X 1 1.504 1.500 1.007 0.999

7 8 2 X 1% 2.005 2000 ' 1.382 1.374 6 7 1% X 1% 1.754 1.750 1.257 ' 1.249

M o . Max. Min. Max. 0-311 0.312 ! 0-312 0.313 0.374 0.375 1 0.375 0.376 0.437 I 0.438 ~ 0.438 0.439 0.499 0-500 ' 0.500 0.501 0.624 ' 0.625 0.625 0.626 0.749- 0.750 0.750 0.751

~~~ ~ ~~ ~ ~ ~

~ ~ .~

0.87< 0.999 1.248 1.498 1.748 1.998

0.875 0.875 0.8'16 1.OOo 1.000 1.001 1.250 1.250 1,252 1.500 1.500 1.502 1.750 1.750 1.752 0 2*000 2400 2.002 2.250 2.250 2.252 8 9 2% X 1% 2.255 , 2.250 1.509 1.499 2.248 1

9 10 2% X 1% 2.505 2.500 1.634 1.624 2.498 2.500 2.500 2.502 10 11 , 2% X 1% 2.755 , 2.750 1.884 1.874 2.748 2.750 2.750 2.752 11 ' 12 3 X 2 3.006 ' 3.000 ' 2.014 1-999 2.998 ' 3.000 3.000 3.002

NOTE. *Th(: k y chamfer hall be the minimum to clear the keyway radius. Nominal values shall

16

BS. 46 : Part 1 : 1958 A N D KEYWAYS, GIB-HEAD OR PLAIN

R R Basic taper I in 100 on this face t ' ( 1 AI

dtered May. 1959

Alternative design showing a parallel extension with a drilled hole to facilitate

extraction Plain taper key

t See B.S. 308--'Engineering drawing practice' for explanation of dimsnrioning tapen.

Depth

shaft H in

Mia I Max. 0.146 ~ 0-152 0.150 ~ 0.156 0.186 0.192 0.190 ' 0.196 0.260 0-266 0.299 0.305 0-370 0.376 0.441 0.447 0.518 0.524 0-599 0.605 0.740 ~ 0.746

0.897 ~ 0.905 0.975 ' 0.983 1.114 1.122

-

_-- - 1 - - ---

0.818 1 0.824

1.195 1.203 1

Depth in hub at deep end of

keyway h

Min. , Max. ~~ -- - ~ ..-

~.

0.090 0.086 0.112 0.108 0.162 0.185 0.239 0.293 0.340 0.384 0.493 0.539 0.581 0.628 0.738 0-782

I 0.096 0.092 0.118 0.114 0.168 0.191 0.245 0.299 0.346 0.390 0-499 0.545 0.589 0.636 0.746 0-790

Nominal 1 keyway : Gibbead radius j

cbamfer r* 1 and key I_- .. .. ~

~ . .

0-010 0.010 0.020 0.020 0.020 0.020 0.062 0.062 0.062 0-062 0.125 0.125 0.125 0.187 0.187 0-187

B i C i

.-

I

be given. For plain keys Columns 17 to 21 do not apply.

17

B.S. 46 : Part 1 : 1958 TABLE 4. SQUARE TAPER KEYS AND

L-- A --/+D4 0

B a s i c t a p e r I in 100 on this f a c e t /

- f

t T

Gib-head key

t-

l I Z ~

Diameter of shaft

/ /' Section at deep end

r of keyway in hub All dimensions

I

Key size 1 I

%6 X 5/16 ~ 0.314 0.312 0.316 ! 0.311

--..___- - , Keyway in , Keyway in shaft hub

Width WS 1 Width Wh ~. _ _ _ ~ ~

Min. 1 Max. ~ Mia. j Max. 0-124 1 0-125 1 0.125 ~ 0-126 0.187 10.188 ~ 0.188 0.189 0.249 1 0.250 1 0.250 0.251 0.311 0.312 ~ 0.312 ' 0.313

-. ~ ____

0.374 0.375 ' 0.375 0.376

NOTE. *The key chamfer shall be the minimum to clear the kcyway radius. Nominal values ar-

18

B.S. 46 : Part 1 : 1958 KEYWAYS, GIB-HEAD OR PLAIN

Basic taper I in 100 on this f a c e t

r , ! I 4 1 I '

0 ' Alternative design showing a parallel

extension wlth a drilled. hole to facilitate extractlon

Plain taper key

t See B.S. 3Ol-'Engineering drawing practicc' for explanation of dimensioning tapers.

are in inches

12 1 13 1 14 I 15 -~ __ -. -

shaft aod hub _____

I Dei& 1 Depth in hub at deep end of

ehaft H keyway h

Mo. I Max. Min. i Max. 0.072 j 0.078 0.039 j 0.045

1-----1-- ,

0.283 1 0.289 0.202 i 0.208 0.354 1 0.360 0.256 1 0.262 0.424 ~ 0.430 ' 0.310 I 0.316

I

16

Nominrl k e m y rndius

chamfer r* Pnd Leg

0.010 0.010 0.010 0.010 0.010 0.020 0.020 0.020 0.020

0-495 ~ 0.501 ' 0.364 i 0.370 0.062 0.566 I 0.572 1 0.418 ~ 0.424 1 OX62

Gibbcid

0.707 I 0.713 1 0.526 i 0.532 0.062 1946 i 0.848 I 0.854 1 0-635 1 0.641 1 0462 1 1x6

given. For plain keys Columns 17 to 21 do not apply.

19

-

I i-

D

0.1 0.2 0-2 0.3 0-3 0.4 0.4 0.5 0.5 0.6 0-6 0.7 0.7

-i

. .

B.S. 46 : Part 1 : 1958

TABLE 5. WOODRUFF 0

All dimensiona ara I

. 2 / 3 - ___ - -. . .

Nominal fractional size of key

1 ~ ..-. ~

KeY and

cutter No.

4 1 5 8 / 9 ~ ~ _ _ _ _ _ _ Depth of key

B

Diameter of key

A

Ihickness of key

C

Width of key- way in shaft 0

D

i - 1 I

i i 1 i i

I

I - . Max.

__ ..- ~~ Min.

0.061 0.093 0.124 0.061 0-093 0-124 0493 0.124 0.155 0.124 0.155 0.187 0.155 0.187 0.249 0.187 0.249 0-311 0.187 0.249

___ Width 1 Dia. Max. Mio. - 1 - Max., 0.171

0.171 0.171 0-203 0.203 0.203 0.250 0.250 0.250 0.313 0-313 0.313 0.375 0.375 0-375 0.4-3 0.438 0-438 0.484 0-484 0.484 0.547 0.547 0-547 0.594 0.594- 0.641 0.641 0.641 -

Min.

0.166 0.166 0-166 0.198 0.198 0.198 0-245 0-245 0.245 0.308 0.308 0.308 0.370 0.370 0.370 0.433 0-433 0.433 0.479 0.479 0.479 0-542 0.542 0-542 0.589 0.589 0.636 0.636 10.636 -

Max.

0.063 0-095 0.126 0.063 0.095 0.126 0.095 0-126 0.157 0.126 0.157 0.189 0-157 0.189 0.251 0.189 0.251 0.313 0.189 0.251 0.313 0.251 0-313 0-376 0.313 0.376 0.251 0.313 0.376 -

Min.

0.062 0.094 0.125 0.062 0.094 0.125 0.094 0.125 0.156 0.125 0.156 0.188 0.156 0.188 0.250 0.188 0.250 0.312 0.188 0-250 0.312 0-250 0.312 0-375 0-312 0.375 0.250 0.312 0.375

203 303 403 204 304 404 305 405 505 406 506 606 507 607 807 608 808 1008 609 809 1009 810 1010 1210 1011 1211 812 1012 1212

0.375 0-375 .-Oe375

0.063 0.095 0.126 0.063 0-095 0.126 0.095 0-126 0.157 0.126 0.157 0.189 0.157 0.189 0-251 0.189 0.251 0.313 0.189 0.251

0.370 0-370 0.370 0.490 0.490 0.490 0.615 0.615 0.615 0.740 0.740 0.740 0.865 0.865 0.865 0.990 0.990 0.990 1.115 1.115 1.115 1.240 1.240 1.240 1.365 1.365 1.490 1.490 1.490

0.750 0.750 0.750 0.875 0.875 0.875 l*OOO 1.OOO 1 W O 1.125 1.125 1.125 1.250 1.250 1.250 1.375 1.375 1.500

I

0.311 1 0.313 0.249 ~ 0.251 0.311 ~ 0.313 0.374 ~ 0.376 0.311 ~ 0-313 0.374 1 0.376 0.249 0.251 0.311 I 0.313 0.374 I 0.376

5/16

i I I ~

j I

i - NOTE. For details of obsolete Woodruff key and cutter numbem referena lould be made to

20

B.S. 46 : Part 1 : 1958

LRadius o.olo 0.005

Optional Design

given in inches

12 1 13 Width 01 keyway ln hub or boss

E

Mln.

0-063 0.095 0-126 0.063 0.095 0.126 0.095 0.126 0-157 0.126 0.157 0.189 0.157 0-189 0.251

. ____

0.189 0.251 0.313 0.251 0.313 0.376 0.313 0.376

MlU.

0.065 0.097 0.128 0.065 0-097 0.128 0.097 0-128 0.159 0.12% 0.159 0.191 0.159 0.191 0.253 0.191

___-

0.253 0.315 0.191 0.253 0.315 0.253 0.315 0.378 0.315 0.378

0.251 0.253 0.313 0.315 0.376 i 0-378

Tab!e 6.

14 1 15 Depth of keyray

in shaft

P

-_

Min.

0.135 0.119 0.104 0.167 0.151 0.136 0-198 0.182 0.167 0-246 0.230 0.214 0-292 0.276 0.245 0-339 0.308 0.277 0.385 0.354 0.323 0.417 0.386 0.354 0.433 0.402 0.511 0.480 0.448

__- - Mal.

0.140 0.124 0.109 0.172 0.156 0-141 0.203 0.187 0.172 0.251 0.235 0.219 0-297 0.281 0.250 0-344 0.313 0.282 0.390 0-359 0-328 0.422 0.391 0.359 0.438 0.407 0.516 0485 0-453

__ ___

i: 16 1 17 Depth 01 k e m y

in hub at entre line

G

_.

T

Min.

0.042 0.057 0.073 0.042 0-057 0.073 0-057 0.073 0.089 0.073 0.089 0.104 0.089 0.104 0.136 0.104 0.136 0.167 0.104 0.136 0.167 0.136 0.167 0-198 0-167 0-198 0.136 0-167 0.198

-

21

~

Max.

0.047 0.062 0.078 0.047 0.062 0.078 0-062 0.078 0.094 0.078 0.094 0.109 0.094 0.109 0.141 0.109 0.141 0.172 0.109 0.141 0.172 0.141 0.172 0.203 0-172 0.203 0.141 0-172 0-203

___

18 1 19 I ___.-

Depth 01 key (optioaal design)

H ____- Max.

0.162 0.162 0.162 0.194 0.194 0.194 0.240 0.240 0-240 0.303 0.303 0-303 0.365 0.365 0.365 0.428 0.428 0-428 0.475 0.475 0.475 0.537 0.537 0.537 0.584 0.584 0.631 0-631 0.631

Min.

0-156 0.156 0-156 0188 0.188 0.188 0.234 0.234 0.234 0.297 0.297 0.297 0.359 0.359 0.359 0.422 0.422 0.422 0.469 0.469 0.469 0.531 0-531 0-531 0.578 0.578 0.625 0.625 0.625 -

20 -~

Dime* sioa J

NOUI.

5/64

364

%4

7 6 4

964

9 6 4

Xe f10 f10 3-56 3-56 Xe 416 ?46 Xe ?46 X6 ? 4 6

5/64

7 6 4

5/64

5/64

5/64

764

342

Y52

7/64

764

764 -

B.S. 46 : Part 1 : 1958

TABLE 6. COMPARISON OF WOODRUFF KEY NUMBERS (WHITNEY, BRITISH AND AMERICAN)

NOTE. This table has been prepared for reference, to help readers to substitute the new numbers (column 4) for the obsolete numbers given in columns 1. 2 and 3.

It is strongly recommended that the obsolete numben should be superseded by the key and Cutter numbers designated in Table 5 of the Specification.

1

Original Wtwp

Cutter and key nmnber

211 212 213

1 2 3

4 5 6

61 7 8

9 91 10

11 12 A

13 14 15

B 152 141

16 17 18

C 161 19

2

Britisb Standard

key numbe~ (obsolete)

3

Britisb Standard

number Cutter

(obsolete)

- - - 1 2 3

4 5 6

- 7 8

9

10

11

A

13

15

B

-

-

-

- - 16

18

C

-

- -

4

British Standard key and Cutter num- ber and American

Cutter oumber

203 303 403

204 304 404

305 405 505

- 406 506

606

507

607

807

608

808

1008

-

-

-

- - 609

809

1009

-

- -

22

5 6

Width :thicLaess)

C

B.S. 46 : Part 1 : 1958

20 21 D

E 22 23

F 24 25

G 126 127

128 129 26

27 28 29

Rx sx Tx

u x v x R

S T U

V 30 31

32 33 34

35 36

2

British Standard

key numbe (obsolete)

1 I

4

British Standard key and cutter num-

ber and Amerlcan Cutter aumber

6

i k e of key

Diameter

A

23

B.S. 46 : Part 1 : 1958 DLMENSIONS OP TANGENTIAL KEYS AND KEYWAYS

6. The dirncnsions of tangential keys and keyways shall be as given in Table 7.

The width of the key (W) is 350 (0.3) of the diameter of the shaft, in which case the thickness of the key (T) becomes ?40 (0.1) of the diameter of the shaft.

Tangential keys should be provided with an extra length for driving. This should not be less than the width of the pair of keys.

24

0

0

0

0

B.S. 46 : Part 1 : 1958

PABLE 7. TANGENTIAL KEYS in. rad on kcywayr 1

Peralkl asscmbled

width

t Tapcr 1 in 100

3/32 in. chamftr at 4S0on k

All dimeosions m in inches

4 4% 4%

4% 5 5%

5% 5% 6

6% 6% 6%

7

8

8%

7%

9

I

I

- Dia-

of sb.ft meter

D

9%

10%

11 11% 12

12% 13 13%

10

14 14% 15

16 17 18

19 20

- Dt-

D f Ib.ft meta

D

21 22 23

24 25 26

27 28 29

30 31 32

33 34 35

36 -

The above dimemions are based on the formulae W = 0.3D and T = 0-1D but for an intermediate diameter of shaft the key section shall bc the same as that for the next size larger shaft in the above List.

25

B.S. 46 : Part 1 : 1958 DIMENSIONS OP KEYS AND KEYWAYS POR MARINE TAILSHAPTS

7. a. General. The dimensions of keys and keyways for marine tai l - shafts shall be as shown in Table 8 and Fig. 2. NOTE. The dimensions of keys for marine tail-shafts should be hased on shaft diameters obtained by Lloyd's rule.

b. Depth at forward end. The keyway in the tailshaft shall be produced in such a manner that, at the forward end of the keyway, the total depth at the side is half the thickness of the key.

C. Position on shaft. The Position of the keyway in the shaft and its relation to the Position of the propeller boss shall be as shown in Fig. 4.

d. Pul1 up on taper. After the propeller nut has been tightened by hand the propeller shall be pulled up on the shaft taper for a distance of 0.006 in. per inch of shaft diameter if the shaft taper is 1 in 12 and 0-008 in. per inch of shaft diameter if the shaft taper is 1 in 16.

e. Sealing arrangements. Sealing arrangements at the forward and after ends of the propeller boss shall be sufficient to prevent ingress of corrosive materials to the tail-shaft under all conditions of Service.

TABLE 8. RECTANGULAR PARALLEL KEYS FOR MARINE

Nominal diameter of shaft at after end On parallel portion

under liner D

inclusive 6 to 6% 7 to 7% 8 to 8% 9 to 9% 10 to 10% 11 to 11% 12 to 12% 13 to 13% 14 to 14% 15 to 15% 16 to 16% 17 to 17% 18 to 18% 19.to 19% 20 to 20% 21 to 21% 22 to 22% 23 to 23% 24 to 24% 25 to 25% 26 to 26% 27 to 27% 28 to 28% 29 to 30

I TAILSHARS

(All dimensions are given in inches)

Nominal dimensions of key

Width W

llrickness T

Fillet radius in keyway

and chamfer On key

R

26

B.S. 46 : Part 1 : 1958

I c u t t e r

Type 1. Sled runner key (preferred method)

Liner

I _ _ _ _ _ _ - - - - - - -

lllllllll!lll Tailshdf t I

Type 2. Rognd ended keyuay (alternative method)

Fig. 2. Types of key and Position of keyway in shaft

27

B.S. 46 : Part 1 : 1958 KEYS AND KEYWAYS FOR TAPERED SHAFI ENDS

8. U. Shufi tupers. The taper on the diameter of the shaft shall be one of those listed below :

1 in 3.428 : Where a self-releasing taper is required. I in 4 : Generally used for locomotive Piston rods, etc. 1 in 5 : Diesel engine fuel injection Pumps. 1 in 8 : Popular in automobile practice ; used by the Society of

Motor Manufacturers and Traders and the Society of Automotive Engineers (American).

1 in 10 : General taper of decimal form. I in 12

1 in 16

6. Keywuys. The keyway shall lie parallel to the side of the cone.

As a result of the Change of section of the shaft along the cone, the depth of keyway at the sides will not be constant. This is illustrated diagrammatically in Fig. 1. (B.S. 308, Engineering drawing practice, Shows the recommended method of dimensioning keyways in tapered shaft ends).

and } : Alternatives used for marine shafting.

\, p r g c diamtttr

/ h a l l diamcttr

/ Fig. 1. Variation in keyway depth in taper shaft W = Width of key. HL = Height of key side at large end of taper. HS = Height of key side at small end of taper. KL = Depth of keyway at large end of taper. KS - Depth ef keyway at small end of taper.

NOTE. KL decreases to KS, and HL increases 10 HS as the diameter ot thz shatt diminishes.

C. Dimensions und toferunces. For the purpose of detennining the correct size of key, the nominal diameter of the shaft shall be that of the iarger end of the cone.

Except in the case of marine tail shaft applications, the dimensions and tolerances of the keys and keyways for coned shafts shall be as shown in Table 1 for keys and keyways of rectangular section, Table 2 for keys and keyways of Square section and Table 5 for Woodruff keys and keyways .

28

B.S. 46 : Part I : 1958

APPENDIX A

PREFERRED LENGTHS OF KEYS

The details of the availability and preferred lengths of plain and gib- head keys, which are given in Tables 9 and 10, have been compiled following an investigation of manufacturing records and are included for reference purposes.

Ir should be noted that no lengths are included for a number of the key sizes which appear in Tables 1, 2, 3 and 4, the reason h i n g that such keys are not normally stocked, and are supplied to customers require- ments.

29

B.S. 46 : Part 1 : 1958

TABLE 9. PREFERRED LENGTHS OF PLAIN KEYS, RECTANGULAR OR SQUARE SECTION, PARALLEL OR TAPER

1

n All dimensions are in inches

T

1

X

X

X

X

X

X

X

Overall length L

% -

X

X

X

X

X

X

X

X

X

X

X

I 3 i / 4 -

X

X

s X

X

X

X

N

X

X

3

X

X

X

X

X

X

X

X

X

X

X

X

i?4

X

r;

X

X

X

X

X

X

X

X

X -

4

X

X

X

X

X

X

X

X

X

X

X I

1

X

X

X

X

X

X

X

NOTE. Larger sizes than those given in this table are not generally stocked but are manufactured to customcrs individual requirements.

30

B.S. 46 : Part 1 : 1958

TABLE 10. PREFERRED LENGTHS OF GIB-HEAD KEYS RECTANGULAR OR SQUARE SECTION

T t , m

L------ L ------4 Lw4 All dimensions are in inches

Overall length L

1 : ~

NOTE. Larger or smaller sizes than those given in this table are not generally stocked but are manufactured to customer's individual requirements.

31

B.S. 46 : Part 1 : 1958

APPENDIX B

APPROXIMATE EQUIVALENTS OF METRIC AND INCH UNITS

Inches

Fractional

%4

%2

364

?4s

964

%n

764

M

Decimal

0.001 0-002 0.003

0.004 0.005 0.006

0.007 0.008 0.009

0.010 0.015 6 0.020 0

0.030 0.031 3 0-040

0.046 9 0.050 0.060

0.062 5 0.070 0.078 1

0-080 0.090 0.093 8

0.100 0.109 4 0.110

0.120 0.125

mm

0.025 0.051 0.076

0.102 0.127 0.152

0.178 0.203 0.229

0.254 0.397 0.508

0.762 0.794 1.016

1.191 1.27 1.524

1.588 1.778 1.984

2.032 2.286 2.381

2.54 2.78 2-79

3.05 3-18

Inches

Fractional Decimal

0.130

0.140 0.140 6 0.150

0-156 3 0.160 0-170

0.171 9 0.180 0.187 5

0.190 0.200 0.203 1

0.218 8 0-234 4 0.250

0-265 6 0.281 3 0.296 9

0.300 0.312 5 0.375

0.400 0.437 5 0.500

0.5625 0.600 0-625

06875

T mm

3.30

3.56 3.57 3-81

3.97 4.06 4.32

4.36

4.76

5-08 5-16

5.56 5-95 6-35

6.75 7.14 7.54

7.62 7.94 9.53

10-16 11.11 12.70

14.29 15.24 15.88

1746

32

Fractional

W

'X6 76

'X6 1

Decimal

0.700 0.750

0.800 0.812 5 0.875

0.900 0-937 5 1.00

2 3 4

5 6 7

8 9 10

11 12 13

14 15 16

17 18 19

20 21 22

W

mm

17-78 19.05

20.32 20.64 22.23

22.86 23-81 25.4

50.8 76.2 101.6

127 152 178

203 229 254

279 305 330

356 381 406

432 457 483

508 533 559

584

B.S. 46 : Part 1 : 1958

IDCk

Fractional mm

Deetmpl

24 25

610 635

26 660 27 686 28 711

29 737 30 762 31 787

32 813 33 838 34 864

35 889 36 914

33

BRITISH STANDARDS The following are available on application: CATALOGUE Including subject index and numerical list of British Standards SECTIONAL LISTS. Gratis Acoustics Aircraft materials and components Building materials and components Chemical engineering Chemicals, fats, oils, scientific apparatus, etc. Cinematography and photography Coal, coke and colliery requisites Codes of Practice Consumer goods Documentation, including Universal Decimal Classification Drawing practice Electrical engineering Farming, dairying and allied interests Furniture, bedding and furnishings Gas and solid fuel and refractories Glasware including scientific apparatus Hospital equipment Illumination and lighting fittings Industrial instruments, etc. Iron and steel Machine tools Mechanical engineering Nomenclature, Symbols and abbreviations Non-ferrous metals Packaging and Containers Paints, varnishes, paint materials and colours for paints Personal safety equipment Petroleum industry Plastics Printing, paper and stationery Road engineering Rubber Shipbuilding Textiles and clothing Welding Applications should be addressed to: B R I T I S H S T A N D A R D S I N S T I T U T I O N Sales Administration Linford Wood, Milton Keynes MK14 6LE (Telephone Milton Keynes (0908) 220022)

BRITISH STANDARDS INSTITUTION

The British Standards Institution was founded in 1901 and incorporated by Royal Charter in 1929.

The principal objects of the Institution as Set out in the Charter are to Co-Ordinate the efforts of Producers and Users for the improvement, standardization and simplification of engineering and industrial materials ; to simplify production and distribution ; to eliminate the waste of time and material involved in the pro- duction of an unnecessary variety of Patterns and sizes of articles for one and the Same purpose ; to Set up Standards of quality and dimensions, and to promote the general adoption of British Standards.

In carrying out its work the Institution enaeavours to ensure adequate representation of all viewpoints. Before embarking on any project it 'must be satisfied that there is a strong body of apinion in favour of proceeding and that there is a recognized need to be met.

The Institution is a non-profit-making concern. It is financed by subscriptions from firms, trade asso- ciations, Professional institutions and other bodies interested in its work, by a Government grant and by the sale of its publications. The demands on the Services of the Institution are steadily increasing and can only be met if continuing and increased financial support is provided.

Membership of the Institution is Open to British subjects, companies, technical and trade associations, and local and public authorities.

9104-6-0.2k-B

Co-Operating organizationsForewordMaterialsParallel keysTaper keysC Tangential keysWoodruff keys

taper keys and keywayskeys and keywayskeywaysmarine tailshafts8 Keys and keyways for tapcrcd shaft endskeybars2 Square parallel keys keyways and keybarsgib-hcad or plainplain5 Woodruff keys and keywaysWhitney, British and Amrican)

7 Tangential keystailshaftssquare section parallel or taper

rectangular or square sectionA Preferred lengths of keysinch units