《BS-906-1-1972.pdf》由会员分享，可在线阅读，更多相关《BS-906-1-1972.pdf（10页珍藏版）》请在三一文库上搜索。
1、BRITISH STANDARD BS 906-1: 1972 Specification for Engineers parallels Part 1: Metric units Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 01:13:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 906-1:1972 This British Standard, having been approved by the Mechan
2、ical Engineering Industry Standards Committee, was published under the authority of the Executive Board on 16 June 1972 BSI 03-1999 First published, 24th June, 1940 First revision, Part 1, June, 1972 The following BSI references relate to the work on this standard: Committee reference MEE/59 Draft f
3、or comment 70/4282 ISBN 0 580 07053 0 Co-operating organizations 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: Ass
4、ociated Offices Technical CommitteeElectricity Council, the Central Electricity Association of Consulting EngineersGenerating Board and the Area Boards in Association of Hydraulic EquipmentEngland and Wales Manufacturers Ltd.Engineering Equipment Users Association Association of Mining Electrical an
5、dGas Council Mechanical EngineersInstitution of Civil Engineers British Chemical Plant ManufacturersInstitution of Gas Engineers AssociationInstitution of Heating and Ventilating British Compressed Air SocietyEngineers British Electrical and Allied ManufacturersInstitution of Mechanical Engineers As
6、sociationInstitution of Mechanical Engineers British Gear Manufacturers Association(Automobile Division) British Internal Combustion EngineInstitution of Plant Engineers Manufacturers AssociationInstitution of Production Engineers* British Mechanical EngineeringLocomotive and Allied Manufacturers Co
7、nfederationAssociation of Great Britain British Pump Manufacturers AssociationLondon Transport Executive British Steel IndustryMachine Tool Trades Association Crown Agents for Oversea Governments andMinistry of Defence AdministrationsMinistry of Defence, Army Department* Department of Employment and
8、 ProductivityNational Coal Board (H.M. Factory Inspectorate)National Physical Laboratory (Department of Department of the EnvironmentTrade and Industry)* Department of Trade and IndustryRoyal Institute of British Architects Department of Trade and industry NationalTelecommunications Engineering Engi
9、neering LaboratoryManufacturing Association Water Tube Boilermakers Association The Government departments and the industrial organization marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British
10、 Standard and were assisted by a number of individual members: Gauge and Tool Makers Association Amendments issued since publication Amd. No.DateComments Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 01:13:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 906-1
11、:1972 BSI 03-1999i Contents Page Co-operating organizationsInside front cover Forewordii 1Scope1 2Material1 3Finish1 4Accuracy1 5Marking1 6Protection4 Appendix Derivation of tolerances stated in Table 1 and Table 2Inside back cover Figure 12 Figure 22 Table 1 Tolerances on grade A parallels2 Table 2
12、 Tolerances on grade B parallels3 Table 3 Basis of tolerancesInside back cover Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 01:13:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 906-1:1972 ii BSI 03-1999 Foreword In order to keep abreast of progress in the i
13、ndustries 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 5000,
14、fully indexed and with a note of the contents of each, will be found in the British Standards Yearbook, which may be purchased from BSI Sales Department. It may also be consulted in many public libraries and similar institutions. This standard makes reference to the following British Standards: BS 8
15、60, Tables for comparison of hardness scales. BS 891, Method for Rockwell hardness test. Part 1: Testing of metals. BS 906, Engineers parallels. Part 2: Imperial units. BS 1133, Packaging code, Section 6: Temporary prevention of corrosion of metal surfaces. This British Standard, prepared under the
16、authority of the Mechanical Engineering Industry Standards Committee, is part of the BSI programme to produce standards in metric units. An earlier British Standard, BS 906, BS 1940, specified engineers parallels in imperial units. This has been revised to become Part 2 of this standard, and will be
17、 withdrawn when the change to metric has been completed. It should therefore be considered as obsolescent. Part 1 of this standard lists a small number of standard sizes which have been chosen consistent with using the parallels individually or in combination over a useful range of reasonably small
18、increments. The sizes are easily called to mind. The tolerances in this Part of this standard are based on formulae shown in an appendix and are inter-related for different dimensions and for the two grades. It should be noted that the tolerances shown in the two parts of the standard differ slightl
19、y. 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 pages This document compris
20、es a front cover, an inside front cover, pages i and ii, pages 1 to 4, 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. Licensed Copy: London S
21、outh Bank University, London South Bank University, Fri Dec 08 01:13:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 906-1:1972 BSI 03-19991 1 Scope This British Standard applies to parallel sided steel blocks of six sizes in Grade A and eight sizes in Grade B, namely: 2 Material Parallels shall be
22、 made of high quality steel, hardened and stabilized by a stress relieving process; the finished parallel shall give a hardness number of not less than 800 HV1) for Grade A and not less than 640 HV1) for Grade B. NOTEThe two largest sizes of Grade B parallels may be made with a series of lightening
23、holes drilled through the thickness, provided that the accuracy of the parallels is not thereby affected. The requirements in this specification may be applied to parallels made of materials other than steel, e.g. granite, provided they are durable. 3 Finish The sides of Grades A and B parallels sha
24、ll have a finely ground, or lapped finish. The ends of both grades of parallels shall be smoothly finished by milling or grinding. All sharp edges shall be removed. 4 Accuracy 4.1 Each parallel and pair of parallels shall comply with the requirements for accuracy for the appropriate grade stated in
25、Table 1 and Table 2. 4.2 Additionally, the maximum errors in squareness of adjacent width and thickness faces shall not exceed 0.005 mm per 25 mm for both Grade A and Grade B parallels.(For widths less than 25 mm the tolerance is 0.005 mm over the width W for both grades.) (See Table 1 and Table 2.)
26、 5 Marking Each parallel shall have legibly and permanently marked on it the following information: the nominal dimensions of T and W (see Table 1 and Table 2), the grade of accuracy, the manufacturers name or trade mark, the serial number common to each parallel of the pair, e.g. 20 mm 40 mm A X Co
27、. 1 234 NOTEAttention is drawn to certification facilities offered by BSI; see the back cover of this standard. GRADE A 5 mm 10 mm 100 mm 10 mm 20 mm 125 mm 15 mm 30 mm 150 mm 20 mm 40 mm 200 mm 25 mm 50 mm 250 mm 30 mm 60 mm 300 mm GRADE B 5 mm 10 mm 100 mm 10 mm 20 mm 125 mm 15 mm 30 mm 150 mm 20
28、mm 40 mm 200 mm 25 mm 50 mm 250 mm 30 mm 60 mm 300 mm 40 mm 80 mm 350 mm 50 mm 100 mm 400 mm NOTE 1See also 2, Material. NOTE 2The titles of the British Standards referred to in this standard are listed on page ii. 1) The equivalent hardness numbers on the Rockwell C scale are 64 for 800 HV, and 57.
29、6 for 640 HV. When Rockwell values are used, tests should be carried out in accordance with BS 891, and it should be noted that conversion values may vary as shown in BS 860. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 01:13:54 GMT+00:00 2006, Uncontrolled C
30、opy, (c) BSI BS 906-1:1972 2 BSI 03-1999 Table 1 Tolerances on grade A parallels 1234567 Nominal size Calliper measurements for individual parallels (see Figure 1) Functional requirements (see Figure 2) Departure from nominal T and W Variations in calliper measurements of T and W for individual para
31、llels for a pair TWL parallelism of T and W matching mmmmmmmmmmmmmm 510100 0.0050.0020.0040.006 1020125 1530150 2040200 2550250 0.0100.0030.0060.010 3060300 NOTETolerance on L is 1 mm throughout. Figure 1 Figure 2 Calliper measurement is the perpendicular distance from any point on one surface to th
32、e corresponding point on the opposite surface. When resting on a true plane, either way up in turn, the variation at any point shall be within the values shown in Column 6 for a single parallel. For matching, the maximum variation over the two parallels, however associated, shall not exceed the tole
33、rance in Column 7. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 01:13:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 906-1:1972 BSI 03-19993 Table 2 Tolerances on grade B parallels 1234567 Nominal size Calliper measurements for individual parallels (see Fig
34、ure 1) Functional requirements (see Figure 2) Departure from nominal T and W Variations in calliper measurements of T and W for individual parallels for a pair TWLparallelism of T and W matching mmmmmmmmmmmmmm 510100 0.0100.0040.0080.012 1020125 1530150 2040200 2550250 0.0200.0060.0120.020 3060300 4
35、080350 0.0250.0070.0140.020 50100400 0.0300.0080.0160.025 NOTETolerance on L is 1 mm throughout. Figure 1 Figure 2 Calliper measurement is the perpendicular distance from any point on one surface to the corresponding point on the opposite surface. When resting on a true plane, either way up in turn,
36、 the variation at any point shall be within the values shown in Column 6 for a single parallel. For matching, the maximum variation over the two parallels, however associated, shall not exceed the tolerance in Column 7. Licensed Copy: London South Bank University, London South Bank University, Fri D
37、ec 08 01:13:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 906-1:1972 4 BSI 03-1999 6 Protection Grade A and B steel parallels shall be protected against climatic conditions by being covered with a suitable corrosion preventative preparation2) during storage and transit. Grade A parallels shall al
38、ways be supplied in pairs and in a suitable protective box. 2) Temporary (easily removable) corrosion preventatives are dealt with fully in BS 1133, Section 6: Guidance on sealed packs with dessicants is given in Section 19, “Use of dessicants in packaging”. Licensed Copy: London South Bank Universi
39、ty, London South Bank University, Fri Dec 08 01:13:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 906-1:1972 BSI 03-1999 Appendix Derivation of tolerances stated in Table 1 and Table 2 The tolerances given in Table 1 and Table 2 of this standard have been calculated on the basis shown in Table 3.
40、Table 3 Basis of tolerances Grade B parallels The tolerances for Grade B parallels are double the respective tolerances calculated for Grade A using the above formulae and the appropriate nominal values of W and L. Tolerances in 4m (0.001 mm = 1 4m) Grade A parallels Calliper measurements for indivi
41、dual parallels (see Figure 1) Functional requirements (see Figure 2) Departure from nominal T and W Variations in calliper measurement of T and W for individual parallels for a pair parallelism of T and W matching Expressed to minimum tolerance 5111 5244 W 10 - L 100 - -+ L 100 - -2 L 100 - -3 L 100
42、 - - Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 01:13:54 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
43、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe
44、 and at the international level. It is incorporated by Royal Charter. Revisions British Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our product
45、s and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel: 020 8996 9000. Fax: 020 8996 7400. BSI offers memb
46、ers 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: 020 8996 9001. Fax: 020 8996 7001
47、. In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and international standar
48、ds through 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: 020 8996 7111. Fax: 020 8996 7048. Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. For details of these and other benefits contact Membership Administration. Tel: 020 8996 7002. Fax: 020 8996 7001. Copyright Copyright subsists in all BSI publications. BSI also