1、BRITISH STANDARD BS 2SP 47: 1957 Incorporating Amendment No. 1 Single coil spring washers for aircraft UDC 629.13:621.882.4BS2SP 47:1957 This British Standard, having been approved by the Aircraft Industry Standards Committee and endorsed by the Chairman ofthe Engineering Divisional Council, was pub
2、lished under theauthority of the General Council of the Institution on 29March 1957 BSI 02-2000 The following BSI references relate to the work on this standard: Committee reference ACE/14 Draft for comment CW(ACE)3739 ISBN 0 580 34434 7 Foreword This revision of BS SP 47:1952 has been undertaken to
3、 provide for 8 B.A. and10 B.A. washers, and to include references to Unified thread sizes. The spring washers covered by this British Standard are designed with close tolerances to give even load distribution and consistent locking properties. A British Standard does not purport to include all the n
4、ecessary 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, pages i and ii, pa
5、ges 1 to 3 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. Amendments issued since publication Amd. No. Date of issue Comments 2891 September 1957 Indicated by a s
6、ideline in the marginBS2SP 47:1957 BSI 02-2000 i Contents Page Foreword Inside front cover 1 Scope 1 2 Material and manufacture 1 3 Dimensions 1 4 Freedom from defects 1 5 Heat treatment 1 6 Hardness 1 7 Protective treatment 1 8 Tests 1 9 Identification 1 Figure 1 Distortion test 2 Figure 2 3 Table
7、1 3ii blankBS2SP 47:1957 BSI 02-2000 1 1 Scope This British Standard specifies the material, dimensions, and finish of precision single coil spring washers for aircraft. 2 Material and manufacture The washers shall be manufactured from steel wire complying with the latest issue of Ministry of Supply
8、 aircraft material specification D.T.D.239, and shall be heat-treated in accordance with the provisions of Clause 5. The grain flow of the material in the washers shall be circumferential. 3 Dimensions The washers, after plating (see Clause 7), shall conform to the dimensions specified in Table 1, a
9、nd shall be of helical form. 4 Freedom from defects The washers shall be free from harmful defects. 5 Heat treatment The washers shall be heat treated by heating to a temperature not exceeding 850 C and quenching in oil. They shall then be tempered to the hardness required in Clause 6. 6 Hardness Th
10、e hardness of the washers shall be not less than D.P.N.500, and not more than D.P.N.550, or approved equivalent. 7 Protective treatment The washers shall be cadmium plated in accordance with the latest issue of Ministry of Supply aircraft process specification D.T.D.904. 8 Tests The purchaser or his
11、 representative may select at random a minimum of two washers from each parcel of three gross or less. If any of the washers selected fail to fulfil the following test requirements four other washers shall be similarly taken from the same parcel and tested. Should all these samples pass the tests th
12、e whole parcel from which the samples were selected shall be regarded as having passed the test. If one or more of the second set of samples fail the whole parcel shall be deemed not to comply with the requirements of this British Standard. a) Compressibility. The samples shall be compressed flat: o
13、n release they shall be free from signs of failure and shall still conform to all the dimensions shown in this specification. b) Distortion. Each sample shall be gripped for the whole of its radial thickness opposite to the gap as shown in Figure 1 and a rod 1 / 64in. less in diameter than the nomin
14、al hole diameter of the washer shall be placed in the hole and turned in a plane parallel with the gripping edge of the vice until the rod prises the points of the washer apart and releases itself through the widened gap. This shall be achieved without signs of cracking. 9 Identification The washers
15、 shall be identified for ordering purposes by the number of this British Standard together with the appropriate code letter shown in Table 1, e.g. washer for nominal 6 / 8in. thread is BS SP 47Q.BS2SP 47:1957 2 BSI 02-2000 Figure 1 Distortion testBS2SP 47:1957 BSI 02-2000 3 Table 1 Figure 2 To suit
16、nominal thread size CodeLetter A B C D Bore Width Free height Thickness max. min. max. min. max. min. max. min. in. in. in. in. in. in. in. in. 10 B.A. 8 B.A. 6 B.A. and No. 4 40 UNC Y Z A 0.071 0.091 0.116 0.068 0.088 0.113 0.033 0.042 0.064 0.028 0.036 0.056 0.060 0.070 0.092 0.040 0.050 0.072 0.0
17、23 0.028 0.041 0.020 0.024 0.036 4 B.A. and No. 6 32 UNC No. 8 32 UNC 2 B.A. and No. 10 32 UNF B X C 0.146 0.168 0.195 0.143 0.165 0.191 0.082 0.090 0.102 0.072 0.080 0.092 0.092 0.100 0.116 0.072 0.080 0.096 0.041 0.045 0.053 0.036 0.040 0.048 1 / 4in. dia. 5 / 16in. dia. 3 / 8in. dia. E G J 0.256
18、0.320 0.383 0.251 0.314 0.376 0.138 0.150 0.170 0.128 0.140 0.160 0.150 0.180 0.200 0.120 0.150 0.170 0.061 0.069 0.077 0.056 0.064 0.072 7 / 16in. dia. 1 / 2in. dia. 8 / 16in. dia. L N P 0.447 0.510 0.574 0.439 0.501 0.564 0.186 0.220 0.240 0.176 0.210 0.230 0.220 0.240 0.270 0.190 0.210 0.240 0.07
19、7 0.085 0.097 0.072 0.080 0.092 5 / 8in. dia. Q 0.636 0.626 0.270 0.260 0.290 0.260 0.109 0.104BS 2SP 47: 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
20、 in Europe and at the international level. It is incorporated by Royal Charter. Revisions BritishStandards 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
21、 products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using 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 mem
22、bers an individual updating service called PLUS which ensures that subscribers automatically receive 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
23、response to orders for international standards, it is BSI policy to supply the BSI implementation of 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 thr
24、ough its Library and its Technical Help to Exporters Service. Various BSI electronic information services 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 stan
25、dards developments and receive substantial discounts on the purchase price of standards. For details 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
26、publications of the international standardization bodies. Except as permitted under the Copyright, Designs 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
27、 permission from BSI. This does not preclude the free use, in the course of implementing the standard, 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.
