1、BRITISH STANDARD BS 2827:1957 Incorporating Amendment No. 1 Specification for Machine screw nuts pressed type B.A. it should also be noted that the maximum minor diameters are slightly larger than those specified for the corresponding sizes of threads in BS93 3)and BS84 4) . Although no great accura
2、cy is called for either on the general dimensions or on the threads, it is considered that the nuts should always be adequate for the kind of work they are normally called upon to do. In preparing this standard, therefore, the aim has been to assist the production of pressed nuts of reasonable quali
3、ty, suitable for many general industrial purposes; they should not, of course, be used where they are subject to appreciable stress. The general dimensions specified for these nuts are based on current practice. Similarity between certain of the hexagon sizes given here and some of those specified f
4、or pressed nuts in BS1981 is purely coincidental. The need to ensure that these nuts can be produced economically would make it difficult to introduce any significant change; it is thought that the use within a single organization both of pressed nuts in accordance with this standard and of those sp
5、ecified in BS1981 is unlikely to be so extensive as to cause serious confusion. In accordance with BSI policy concerning the introduction of metric standards, this imperial standard has been declared obsolescent. It will be made obsolete in due course. A British Standard does not purport to include
6、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 pages This document comprises a front cover, an inside front cover, pagesi an
7、dii, pages1 to3 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. 1) BS 57, “B.A. screws, bolts, nuts and plain washers”. 2) BS1083, “Precision hexagon bolts, screws
8、, nuts and plain washers (B.S.W. and B.S.F. threads)”. 3) BS93, “B.A. screw threads”. 4) BS84, “Parallel screw threads of Whitworth form”.BS2827:1957 BSI 01-2000 1 1 Scope This British Standard relates to pressed nuts in ferrous or non-ferrous material, having B.A. or Whitworth form threads. General
9、 dimensions are given for square and hexagon nuts. The nuts specified in this standard are suitable for many general purposes but should not be used where they are subject to appreciable stress. 2 Material Steel nuts shall be manufactured from cold rolled strip, and brass nuts shall be manufactured
10、from cold rolled or extruded strip. The material shall have a tensile strength of not less than the following: If the purchaser requires the nuts to be manufactured from steel or brass of a higher tensile strength or of another material, he should specify the tensile strength and the material. 3 Dim
11、ensions The dimensions and tolerances for nuts shall be as specified inTable 1, Table 2, Table 3 andTable 4 andClause4. 4 Screw threads a) General. The screw threads shall be of one of the following series as specified by the purchaser: British Association (B.A.) in accordance with BS93, “B.A. screw
12、 threads”, British Standard Whitworth (B.S.W.), British Standard Fine (B.S.F.) or Whitworth series (Whit.) in accordance with BS84, “Parallel screw threads of Whitworth form”. NOTEBasically, the dimensions of these threads are in accordance with the standards quoted; the minimum major and effective
13、diameters are as given in BS93 and BS84 respectively, but the maximum minor diameters are slightly larger than those of standard screw threads. The axis of the screw thread shall be reasonably square with the face of the nut and reasonably central with the square or hexagon. b) B.A. screw threads. B
14、.A. screw threads shall conform to the limits and tolerances specified inTable 2 of this standard. See Note to sub-clausea) above. c) B.S.W., B.S.F. and other Whitworth screw threads. B.S.W., B.S.F. and other Whitworth screw threads shall conform to the limits and tolerances specified inTable 3 andT
15、able 4 of this standard. See Note to sub-clausea) above. Steel 25 tons/sq. in. Brass 20 tons/sq. in.BS2827:1957 2 BSI 01-2000 Table 1 Machine screw nuts, pressed type, square and hexagon GENERAL DIMENSIONS Figure 1 Square nut Figure 2 Hexagon nut 1 2 3 4 5 6 7 Nominal size of nut, D Width across fla
16、ts, A Width across corners Thickness, E Square, B Hexagon, C Whitworth B.A. Nominal Max. Min. Max. Min. Max. Min. in. in. in. in. in. in. in. 3 / 32 48 Whit. a 1 / 8 40 B.S.W. a 5 / 32 32 Whit. a 6 B.A. 5 B.A. a 4 B.A. & 3 B.A. a 0.250 0.250 0.312 0.244 0.244 0.306 0.353 0.353 0.442 0.289 0.289 0.36
17、1 0.082 0.082 0.095 0.078 0.078 0.091 3 / 16 24 B.S.W. 3 / 16 32 B.S.F. a 7 / 32 24 Whit. a 7 / 32 28 B.S.F. a 2 B.A. 1 B.A. a 0.375 0.437 0.369 0.429 0.530 0.619 0.433 0.505 0.106 0.128 0.102 0.123 1 / 4 20 B.S.W. 1 / 4 26 B.S.F. 5 / 16 18 B.S.W. 5 / 16 22 B.S.F. 0 B.A. 0.500 0.562 0.492 0.552 0.70
18、7 0.795 0.577 0.649 0.128 0.160 0.123 0.154 3 / 8 16 B.S.W. 3 / 8 20 B.S.F. 0.625 0.615 0.884 0.722 0.179 0.173 a These sizes are non-preferred and should be dispensed with wherever possible.BS2827:1957 BSI 01-2000 3 5 Gauging The quality of these nuts does not call for any very precise system of ga
19、uging. To ensure that they will assemble freely on external threads of basic size and that the nuts have an adequate depth of thread, it is recommended that they be checked merely by means of a GO screw plug gauge and a NOT GO plain plug for the minor diameter, made to the appropriate tolerances as
20、specified in BS919, “Screw gauge limits and tolerances”. It is not considered necessary to use a NOT GO effective diameter gauge on these nuts, and accordingly no maximum effective diameter is specified in the tables. Table 2 Limits for British Association (B.A.) screw threads Table 3 Limits for B.S
21、.W. and other Whitworth screw threads Table 4 Limits for B.S.F. screw threads See Clause4 a) and NOTE and Clause5 1 2 3 4 Nominal sizeof nut, D Major diameter Effective diameter Minor diameter Minimum (basic) Minimum (basic) Maximum in. in. in. 6 B.A. 5 B.A. a 4 B.A. 0.1102 0.1260 0.1417 0.0976 0.11
22、20 0.1262 0.095 0.109 0.123 3 B.A. a 2 B.A. 1 B.A. a 0 B.A. 0.1614 0.1850 0.2087 0.2362 0.1441 0.1659 0.1874 0.2126 0.140 0.162 0.182 0.207 a These sizes are non-preferred and should be dispensed with wherever possible. See Clause 4 a) and NOTE and Clause 5 1 2 3 4 Nominal sizeofnut,D Major diameter
23、 Effective diameter Minor diameter Minimum (basic) Minimum (basic) Maximum in. in. in. 3 / 32 48 Whit. a 1 / 8 40 B.S.W. a 5 / 32 32 Whit. a 0.0937 0.1250 0.1562 0.0804 0.1090 0.1362 0.077 0.104 0.129 3 / 16 24 B.S.W. 7 / 32 24 Whit. a 1 / 4 20 B.S.W. 0.1875 0.2187 0.2500 0.1608 0.1920 0.2180 0.152
24、0.183 0.208 5 / 16 18 B.S.W. 3 / 8 16 B.S.W. 0.3125 0.3750 0.2769 0.3350 0.265 0.321 a These sizes are non-preferred and should be dispensed with wherever possible. See Clause 4 a) and NOTE and Clause 5 1 2 3 4 Nominal sizeofnut,D Major diameter Effective diameter Minor diameter Minimum (basic) Mini
25、mum (basic) Maximum in. in. in. 3 / 16 32 B.S.F. a 7 / 32 28 B.S.F. a 1 / 4 26 B.S.F. 0.1875 0.2187 0.2500 0.1675 0.1959 0.2254 0.161 0.188 0.216 5 / 16 22 B.S.F. 3 / 8 20 B.S.F. 0.3125 0.3750 0.2834 0.3430 0.273 0.333 a These sizes are non-preferred and should be dispensed with wherever possible.BS
26、 2827:1957 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions BritishSta
27、ndards are updated by amendment or revision. Users of BritishStandards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while usin
28、g this BritishStandard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel:02089969000. Fax:02089967400. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive
29、 the latest editions of standards. Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services. Tel:02089969001. Fax:02089967001. In response to orders for international standards, it is BSI policy to supply the BSI implementation of
30、 those that have been published as BritishStandards, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service. Various BSI electronic information ser
31、vices are also available which give details on all its products and services. Contact the Information Centre. Tel:02089967111. Fax:02089967048. Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. For details
32、 of these and other benefits contact Membership Administration. Tel:02089967002. Fax:02089967001. Copyright Copyright subsists in all BSI publications. BSI also holds the copyright, in the UK, of the publications of the international standardization bodies. Except as permitted under the Copyright, D
33、esigns and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise without prior written permission from BSI. This does not preclude the free use, in the course of implementing the standar
34、d, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel:02089967070.
