1、BRITISH STANDARD BS 6102-9: 1990 ISO 6696:1989 Cycles Part 9: Specification for screw threads used in bottom bracket assembliesBS6102-9:1990 This British Standard, having been prepared under the directionof the General Mechanical Engineering Standards Policy Committee, waspublished under the authori
2、tyof the Board of BSI andcomes into effect on 30November 1990 BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference GME/25 Draft for comment 89/70615 DC ISBN 0 580 19111 7 Committees responsible for this British Standard The preparation of this British Sta
3、ndard was entrusted by the General Mechanical Engineering Standards Policy Committee (GME/-) to Technical Committee GME/25, upon which the following bodies were represented: Association for Consumer Research Association of Cycle Traders Bicycle Association of Great Britain British Battery Manufactur
4、ers Association British Cycling Federation British Rubber Manufacturers Association British Society for the Prevention of Accidents Consumer Policy Committee of BSI Cyclist Touring Club Department of Trade and Industry Department of Transport Institute of Trading Standards Administration Small Elect
5、rical Appliances Marketing Association Individual manufacturers of cycles Amendments issued since publication Amd. No. Date CommentsBS6102-9:1990 BSI 08-1999 i Contents Page Committees responsible Inside front cover National foreword ii Introduction 1 1 Scope 1 2 Normative references 1 3 Basic ISO t
6、hread profile and basic sizes 1 4 Limits and tolerances 2 5 Designation 2 6 Gauging system 2 Figure 1 Basic profiles of British Standard Cycle and ISO threads 5 Figure 2 Thread profiles and tolerance zones for ISO bottom bracket shell and cup threads 6 Table 1 Basic dimensions 2 Table 2 Limits and t
7、olerances for screw threads on cups 2 Table 3 Limits and tolerances for screw threads on bottom bracket shell 3 Table 4 Cup Limits of size for GO screw ring and calliper gauges, and associated screw check, wear and setting plugs 3 Table 5 Cup Limits of size for NOT GO screw ring and calliper gauges,
8、 and associated screw check, wear and setting plugs 4 Table 6 Shell Limits of size for GO and NOT GO screw plug gauges 4 Table 7 Cup and shell Limits of size for GO and NOT GO plain ring or calliper gauges for cup major diameter, and GO and NOT GO plain plug gauges for shell minor diameter 4 Publica
9、tion(s) referred to Inside back coverBS6102-9:1990 ii BSI 08-1999 National foreword This Part of BS 6102 has been prepared under the direction of the General Mechanical Engineering Standards Policy Committee and forms Part of a series implementing corresponding international standards in the develop
10、ment of which the UK has played an active part. This standard is identical with ISO6696:1989 “Cycles Screw threads used in bottom bracket assemblies”, which was prepared by Technical Committee ISO/TC149 of the International Organization for Standardization (ISO). A British Standard does not purport
11、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. Cross-references International standard Corresponding British Standard BS3643
12、 ISO metric screw threads ISO68:1973 ISO965:1980 Part1:1981 Principles and basic data (Technically equivalent) ISO1502:1978 BS919 Specification for screw gauge limits and tolerances Part3:1968 Gauges for ISO metric screw threads (Technically equivalent) Summary of pages This document comprises a fro
13、nt cover, an inside front cover, pages i and ii, pages1 to6, 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.BS6102-9:1990 BSI 08-1999 1 Introd
14、uction Inch screw threads of British Standard Cycle (B.S.C.) thread profile are used extensively throughout the world for various applications on bicycle components, and have been standardized in national standards. The purpose of this document is to provide an International Standard for the particu
15、lar screw thread used to assemble bottom bracket cups to bottom brackets on bicycles: it is based on the use of the ISO basic thread profile and complies as far as is practicable with existing International Standards for general purpose screw threads. The change to an ISO system of screw threads wil
16、l inevitably take a long time to complete in view of the millions of bicycles now in use which employ B.S.C. thread profile inch screw threads and for which replacement spare parts will be required. For this reason, in order to minimize changes in production methods during the change to the Internat
17、ional Standard, and also to secure satisfactory interchangeability with the B.S.C. screw threads now used, the ISO screw thread in this International Standard has the same pitch as that of the1,37 in 24 t.p.i. B.S.C. screw thread it is intended to replace; this means that the pitch is in inch units
18、(turns per inch or t.p.i.) but all other dimensions are specified in metric units. A1 3/8 (1,375) in 24 t.p.i screw thread of ISO basicprofile has been adopted in this International Standard. The basic pitch diameter of this threaddiffers by only0,003 mm from that of the1,37 in 24 t.p.i. B.S.C. thre
19、ad, but, due to thesmaller crest truncation of the ISO profile (seeFigure 1) interference may occur at the major diameter when an ISO cup thread made towards its upper limit is assembled with a B.S.C. shell thread made towards its lower limit on major diameter. The possibility of interference occurr
20、ing in this manner is considered to be unlikely in practice because of the effect of the manufacturing tolerances (negative on the cup and positive on the shell) and the usual practice of using high-crested screwing taps. 1 Scope This International Standard specifies the thread profile and limits an
21、d tolerances for the screw threads used to assemble bottom bracket cups to bottom brackets on bicycles (adjustable cups with right-hand thread, fixed cups with left-hand thread). It is based on a) the use of the ISO basic thread profile given in ISO68; b) satisfactory interchangeability with the cor
22、responding British Standard Cycle (B.S.C.) thread; this has required the use of an inch pitch (t.p.i.); c) the use of screw thread tolerance grades and tolerance positions given in ISO965-1; d) the use of gauges made to ISO1502. 2 Normative references The following standards contain provisions which
23、, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility o
24、f applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO68:1973, ISO general purpose screw threads Basic profile. ISO965-1:1980, ISO general purpose metric screw threads Tolerances Part1: Principle
25、s and basic data. ISO1502:1978, ISO general purpose metric screw threads Gauging. 3 Basic ISO thread profile and basic sizes 3.1 Basic profile The basic profile is that given in ISO68 and is shown in Figure 1. It is the theoretical profile associated with the basic sizes of the major, pitch and mino
26、r diameters of the screw thread. 3.2 Basic sizes The basic major diameter, and the basic pitch and minor diameters determined from the basic profile, are given in Table 1.BS6102-9:1990 2 BSI 08-1999 Table 1 Basic dimensions 4 Limits and tolerances 4.1 Fundamental deviations and maximum material limi
27、ts The fundamental deviations are applied to the basic diameters and establish the maximum material limits. For the thread on the cups the fundamental (upper) deviations are negative and correspond to tolerance position “g” on the pitch and minor diameters, and to tolerance position “e” on the major
28、 diameter. For the threads on the shell the fundamental (lower) deviations are zero and correspond to tolerance position “H” on the major, pitch and minor diameters. NOTEA fundamental deviation of position “e” on the major diameter of the cups is necessary on thin-walled components to be able to for
29、m the thread by rolling, without the removal of metal. 4.2 Tolerance grades, tolerances and limits of size The application of tolerances to the maximum material limits, negative tolerances for the thread on the shell and positive tolerances for the threads on the cups determines the minimum material
30、 limits of size. The tolerances and limits of size are given in Table 2 and Table 3 respectively for the cups and the shell. The tolerances are grade6 except for the major diameter of the cups where it is grade8, in accordance with ISO965-1. The fundamental deviations and tolerance zones are shown i
31、n Figure 2. 5 Designation Screw threads made to this International Standard are designated by a) the nominal diameter of the thread in inches; b) the pitch of the thread in t.p.i.; c) the respective tolerance classes of the cup and shell threads; d) the direction: right- or left-hand. EXAMPLE Adjust
32、able cup and side of the shell away from the chainwheel: 1,375 24 6H/6g8e right-hand Fixed cup and side of the shell towards the chainwheel: 1,375 24 6H/6g8e left-hand 6 Gauging system The gauging system is that laid down in ISO1502 to which reference should be made for details of the thread profile
33、s of the screw gauges and the method of gauge application. ISO1502 gives formulae for the calculation of the gauge limits. These formulae have been used to calculate the gauge limits for the shell and cup in this International Standard, and these limits are given in Table 4 to Table 7. It should be
34、noted that the pitch diameter limits given in Table 4 to Table 6 relate to the simple pitch diameter, and separate tolerances are given in ISO1502 for the pitch and flank angles of these gauges. These tolerances are Pitch tolerance = 0,005 mm Flank angle tolerance Table 2 Limits and tolerances for s
35、crew threads on cups Nominal diameter of thread in t.p.i. Basic sizes, mm Major diameter Pitch diameter Minor diameter 1,375 24 34,925 34,238 33,779 = 0 15 for profiles with complete flanks; = 0 16 for profiles with truncated flanks. t.p.i. Major diameter d mm Pitch diameter d 2 mm Minor diameter d
36、1 mm max. tol. min. max. tol. min. max. 24 34,865 0,280 34,585 34,212 0,125 34,087 33,639 1 2 3 4 5 6 7 8 NOTE1The tolerances given in columns3 and6 are those recommended in ISO965-1 for the nearest metric pitch corresponding to the t.p.i. given in column1. NOTE2The limit for the maximum minor diame
37、ter corresponds to a maximum truncation of3H/16: this conforms to the specifications for the root contour of external threads given in ISO965-1. NOTE3The adjustable cup has a right-hand thread, and the fixed cup a left-hand thread.BS6102-9:1990 BSI 08-1999 3 Table 3 Limits and tolerances for screw t
38、hreads on bottom bracket shell Table 4 Cup Limits of size for GO screw ring and calliper gauges, and associated screw check, wear and setting plugs t.p.i. Major diameter, D mm Pitch diameter, D 2 mm Minor diameter, D 1 mm D 3min. D min. max. tol. min. max. tol. min. 24 35,001 34,925 34,408 0,170 34,
39、238 34,015 0,236 33,779 1 2 3 4 5 6 7 8 9 NOTE1The tolerances given in columns5 and8 are those recommended in ISO965-1 for the nearest metric pitch corresponding to the t.p.i. given in column1. NOTE2The grade6 pitch diameter tolerance differs from the grade6 minor diameter tolerance. NOTE3D 3min. is
40、 the diameter to the radiused root of the shell thread that just clears the crest of a maximum cup thread, assuming no clearance between the flanks of the assembled threads. NOTE4Note that the bottom bracket shell of a bicycle incorporates two threads in accordance with Table 3, one a right-hand thr
41、ead (on the opposite side to the chainwheel) the other a left-hand thread (on the side next to the chainwheel). Dimensionsinmillimetres Type of gauge Major diameter Pitch diameter Minor diameter max. min. max. min. max. min. Solid GO screw ring gauge 34,984 34,217 34,203 33,760 33,746 Adjustable GO
42、screw ring gauge 34,984 Set on setting plug 33,760 33,746 GO screw calliper gauge Cleared Distance from pitch line to crest is 0,229 5 GO screw check plug for new solid GOscrew ring gauge 34,908 34,890 34,199 34,191 33,583 NOT GO screw check plug for new solid GO screw ring gauge 34,433 5 34,424 5 3
43、4,221 34,213 33,593 Wear check plug for solid or adjustable GO screw ring gauge 34,442 5 34,433 5 34,230 34,222 33,593 Setting plug for GO screw calliper gauge 34,908 34,890 34,199 34,191 33,583 Full profile setting plug for adjustable GO screw ring gauge 34,908 34,890 34,210 34,202 33,593 Truncated
44、 profile setting plug for adjustable GO screw ring gauge 34,422 5 34,413 5 34,210 34,202 33,593BS6102-9:1990 4 BSI 08-1999 Table 5 Cup Limits of size for NOT GO screw ring and calliper gauges, and associated screw check, wear and setting plugs Table 6 Shell Limits of size for GO and NOT GO screw plu
45、g gauges Table 7 Cup and shell Limits of size for GO and NOT GO plain ring or calliper gauges for cup major diameter, and GO and NOT GO plain plug gauges for shell minor diameter Dimensionsinmillimetres Type of gauge Major diameter Pitch diameter Minor diameter max. min. max. min. max. min. Solid NO
46、T GO screw ring gauge Cleared 34,908 34,087 34,073 33,882 33,854 Adjustable NOT GO screw ring gauge Cleared 34,908 Set on setting plug 33,882 33,854 NOT GO screw calliper gauge Thread profile sizes as for NOT GO screw ring gauge GO screw check plug for new solid NOTGO screw ring gauge 34,908 34,890
47、34,069 34,061 33,453 NOT GO screw check plug for new solid NOT GO screw ring gauge 34,783 34,765 34,091 34,083 33,475 Wear check plug for solid or adjustable NOT GO screw ring gauge 34,788 34,770 34,096 34,088 33,475 Setting plug for NOT GO screw calliper gauge 34,783 34,765 34,080 34,072 33,453 Ful
48、l profile setting plug for adjustable NOT GO screw ring gauge 34,776 34,758 34,080 34,072 33,475 Truncated profile setting plug for adjustable NOT GO screw ring gauge 34,297 34,279 34,080 34,072 33,475 Dimensionsinmillimetres Type of gauge Major diameter Pitch diameter Minor diameter New gauge Worn
49、gauge max. min. max. min. min. max. GO screw plug gauge 34,948 34,926 34,255 5 34,244 5 34,232 5 33,626 NOT GO screw plug gauge 34,636 5 34,614 5 34,419 34,408 34,402 33,626 Dimensionsinmillimetres Type of gauge GO gauge NOT GO gauge New gauge Worn gauge max. min. max. min. Plain ring or calliper gauge 34,835 34,819 34,865 max. 34,593 34,577 Plain plug gauge 33,825 33,809 33,779 min. 34,023 34,007BS6102-9:1990 BSI 08-1999 5 Figure 1 Basic profiles of British Standard Cycle and ISO threadsB
