1、BRITISH STANDARD BS3401:1961 Incorporating Amendment No.1 Specification for Beryllium copper crinkle washersBS3401:1961 This BritishStandard, having been approved by the MechanicalEngineering IndustryStandards Committeeand endorsed bytheChairman of the Engineering Divisional Council,was published un
2、dertheauthority of the GeneralCouncil on 20July1961 BSI02-2000 The following BSI references relate to the work on this standard: Committee reference MEE/134 and MEE/134/1 Draft for comment CY(MEE)9051 ISBN 0 580 34356 1 Co-operating organizations The Mechanical Engineering Industry Standards Committ
3、ee, under whose supervision this BritishStandard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Admiralty Gas Council Air Ministry High Commission of India Associated Offices Technical Committee Institute of Marine Eng
4、ineers Association of Consulting Engineers Institute of Petroleum (Incorporated) Institution of Civil Engineers British Chemical Plant Manufacturers Institution of Gas Engineers Association Institution of Heating and Ventilating British Compressed Air Society Engineers British Electrical and Allied
5、Manufacturers Institution of Mechanical Engineers Association* Institution of Mechanical Engineers British Engineers Association* (Automobile Division) British Gear Manufacturers Association Institution of Production Engineers* British Internal Combustion Engine Locomotive and Allied Manufacturers M
6、anufacturers Association Association of Great Britain British Iron and Steel Federation Machine Tool Trades Association British Railways, The British Transport Ministry of Labour (Factory Inspectorate) Commission Ministry of Power Crown Agents for Oversea Governments and Ministry of Transport Admini
7、strations Ministry of Works D.S.I.R.National Engineering Laboratory National Coal Board Electricity Council, The Generating Board and National Physical Laboratory (D.S.I.R) the Area Boards in England and Wales Radio Industry Council Engineering Equipment Users Association War Office The organization
8、s 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: Coil Spring Federation Research Organization Society of Motor Manufacturers and Copper Development Association Traders Ltd. Ministry o
9、f Aviation Telecommunication Engineering and Post Office Manufacturing Association Individual manufacturers Amendments issued since publication Amd. No. Date of issue Comments 4125 November 1982 Indicated by a sideline in the marginBS3401:1961 BSI 02-2000 i Contents Page Co-operating organizations I
10、nside front cover Foreword ii 1 Scope 1 2 Nomenclature 1 3 Material 1 4 Finish 1 5 Freedom from defects 1 6 Dimensions 1 7 Closing and test for permanent set 1 8 Sampling procedure 1 Table 1 Dimensions of beryllium copper crinkle washers 2BS3401:1961 ii BSI 02-2000 Foreword This standard makes refer
11、ence to the following BritishStandards: BS427, Vickers hardness test. Part1. Testing of metals. BS2870, Rolled copper and copper alloy sheet, strip and foil. This BritishStandard has been prepared under the authority of the Mechanical Engineering Standards Committee in response to requests from manu
12、facturers of crinkle washers. The use of this type of washer has been steadily increasing in recent years and it is widely used in a number of industries. It has accordingly been felt that it would be desirable to provide a standard range of crinkle washers before too many variations become establis
13、hed in practice and it is hoped that the washers specified in this standard will meet most normal requirements. It is restricted for the time being to washers made from beryllium copper, but it is likely that the standardization of crinkle washers made from other materials will be considered at a fu
14、ture date. NOTEWhere metric equivalents are stated the figures in British units are to be regarded as the standard. The metric conversions are approximate. More accurate conversions should be based on the tables in BS350, “Conversion factors and tables”. A British Standard does not purport to includ
15、e 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
16、andii, pages1 and 2, 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.BS3401:1961 BSI 02-2000 1 Obsolescent (by Amendment No.1). The need for th
17、e product covered by this BritishStandard has been reviewed and it has been decided that, in the interests of rationalization, it should be regarded as obsolescent and not therefore used for new designs. The standard will be withdrawn in due course. 1 Scope This standard specifies dimensions and tol
18、erances and general requirements for a range of beryllium copper crinkle washers suitable for use with screwed fasteners in sizes from0.060in (American No.0) to 3 / 4in(1.5mm to19mm) nominal diameter. 2 Nomenclature For the purpose of this BritishStandard, the washers shall be known as “Beryllium co
19、pper crinkle washers”. 3 Material The material used for the manufacture of these washers shall be such that after suitable heat treatment the products, when tested in accordance with the provisions of BS427, “Vickers hardness test”, have a hardness of350 to380H.V. 1)and are capable of meeting the te
20、st requirements specified in Clause7. This material shall be in accordance with the requirements for CB.101 beryllium copper as specified in BS2870, “Rolled copper and copper alloy sheet, strip and foil”. 4 Finish Beryllium copper crinkle washers complying with this BritishStandard shall be of self-
21、colour finish. NOTEIf washers are required to have any other specified finish, e.g.cadmium plating, this shall be agreed between purchaser and manufacturer. 5 Freedom from defects The surfaces of the washers shall be clean, smooth and free from scale or harmful defects. 6 Dimensions The dimensions o
22、f the finished washers in the unplated condition shall be in accordance with Table 1. 7 Closing and test for permanent set Sample washers shall be selected from batches in accordance with Clause8. The samples shall be completely closed; on release of the pressure the overall height of each washer sh
23、all be not less than twice its sectional thickness. This application and removal of pressure shall then be repeated twenty times in quick succession, after which its overall height shall not have been reduced to less than1.8times its sectional thickness. 8 Sampling procedure a) Definition of a batch
24、. For the purposes of this standard a batch shall consist of a number of washers of the same size made from material of the same strip (or cast). b) Sample and number of tests. For the test specified in Clause7, five washers shall be selected from a batch and if there are no failures in this sample
25、the batch shall be deemed to comply with the requirements of this standard. Should any specimen in this sample fail to meet the test, a further sample of five washers shall be selected from the batch which shall be deemed to comply with the requirements of this standard if there is one failure in th
26、e original sample and one failure in the second sample. If there is one failure in the original sample and two or more failures in the second sample or more than one failure in the original and one or more in the second sample, the batch shall be deemed not to comply with the requirements of this st
27、andard. 1) Diamond Pyramid Number.BS3401:1961 2 BSI 02-2000 Table 1 Dimensions of beryllium copper crinkle washers 1 2 3 4 5 6 7 8 9 10 Nominal size Internal diameter A External diameter B Height C Thickness D American No. size B.A. a size max. min. max. min. max. min. nominal tolerance b in in in i
28、n in in in in 0 10 0.080 0.075 0.155 0.145 0.020 0.014 0.0060 0.0005 1 9 0.088 0.083 0.165 0.155 0.021 0.015 0.0060 2 8 0.100 0.095 0.211 0.201 0.021 0.015 0.0060 3 7 0.111 0.106 0.220 0.210 0.021 0.015 0.0060 4 6 0.130 0.125 0.255 0.245 0.024 0.018 0.0060 5 5 0.139 0.134 0.270 0.260 0.024 0.018 0.0
29、060 6 4 0.157 0.152 0.305 0.295 0.031 0.025 0.0084 0.0006 8 3 0.181 0.176 0.345 0.335 0.033 0.027 0.0108 0.0008 10 2 0.208 0.203 0.380 0.370 0.035 0.029 0.0124 12 0 0.256 0.251 0.505 0.495 0.045 0.039 0.0148 0.0010 in 1 / 4 0.271 0.266 0.505 0.495 0.045 0.039 0.0148 5 / 16 0.337 0.332 0.605 0.595 0.
30、055 0.049 0.0148 3 / 8 0.411 0.406 0.705 0.695 0.067 0.061 0.0220 0.0012 7 / 16 0.474 0.469 0.825 0.815 0.075 0.065 0.0220 1 / 2 0.536 0.531 0.955 0.945 0.081 0.071 0.0220 5 / 8 0.661 0.656 1.175 1.165 0.095 0.085 0.0280 3 / 4 0.786 0.781 1.395 1.385 0.105 0.085 0.0280 a The sizes in heavy type are
31、those indicated as preferred in BS57, “B.A. screws, bolts, nuts and plain washers”. b These tolerances are in accordance with the normal tolerance specified for the material in Table1 of BS2870, “Rolled copper and copper alloy sheet, strip and foil”, for strip up to and including6in wide. BS3401:196
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