1、July 2016 English price group 9No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 21.040.30; 43.150!%XLP“2534145www.di
2、n.deDIN ISO 8488Cycles Screw threads used to assemble head fittings on bicycle forks (ISO 8488:1986),English translation of DIN ISO 8488:2016-07Fahrrder Gewinde fr Steuersatz und Fahrradgabel (ISO 8488:1986),Englische bersetzung von DIN ISO 8488:2016-07Cycles Filetages utiliss pour lassemblage des “
3、accessoires“ de direction sur les fourches de bicyclettes (ISO 8488:1986),Traduction anglaise de DIN ISO 8488:2016-07www.beuth.deDocument comprises 12 pagesDTranslation by DIN-Sprachendienst.In case of doubt, the German-language original shall be considered authoritative.08.16DIN ISO 8488:2016-07 2
4、A comma is used as the decimal marker. Start of application The start of application of this standard is 2016-07-01. Contents Page National foreword . 3 National Annex NA (informative) Bibliography 4 0 Introduction . 5 1 Scope and field of application 6 2 References 6 3 Basic ISO thread profile and
5、basic sizes . 6 3.1 Basic profile 6 3.2 Basic sizes . 6 4 Limits and tolerances . 6 4.1 Fundamental deviations and maximum material limits . 6 4.2 Tolerance grades, tolerances and limits of size 7 5 Designation . 7 6 Gauging system . 7 DIN ISO 8488:2016-07 3 National foreword This standard includes
6、safety requirements within the meaning of the Produktsicherheitsgesetz (ProdSG) (German Product Safety Act). This document (ISO 8488:1986) has been prepared by Technical Committee ISO/TC 149 “Cycles”. The responsible German body involved in its preparation was DIN-Normenausschuss Sport- und Freizeit
7、gert (DIN Standards Committee Sports Equipment), Working Committee NA 112-06-01 AA Fahrrder fr allgemeine und sportliche Benutzung. Attention is drawn to the possibility that some elements of this document may be the subject of patent rights. DIN and/or DKE shall not be held responsible for identify
8、ing any or all such patent rights. Where this standard has been identified by the Ausschuss fr Produktsicherheit (German Committee for Product Safety) and reference to it has been published in the Gemeinsames Ministerialblatt (German Joint Ministerial Gazette) by the Bundesanstalt fr Arbeitsschutz u
9、nd Arbeitsmedizin (BAuA) (German Federal Institute for Occupational Safety and Health), it is to be presumed that screw threads used to assemble head fittings on bicycle forks, which comply with this standard fulfil the relevant health and safety requirements. In addition to the legal units of measu
10、rement, this standard also uses the unit “inch”. It should, however, be noted that the Gesetz ber Einheiten im Messwesen (German Law on units in metrology) prohibits the use of this unit for official and commercial purposes in Germany. Conversion: Unit not permitted Unit permitted Conversion in (inc
11、h) mm 1 inch = 25,4 mm The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 68 No national standard available at the time (current edition DIN ISO 68-1*) ISO 965-1 DIN ISO 965-1 (current edition DIN ISO 965-1:1999-11) ISO 1502 DIN ISO 1502 (
12、current edition DIN ISO 1502:1996-12) ISO 6692 DIN ISO 6692 *) ISO 68 was withdrawn and replaced by two parts (ISO 68-1 and ISO 68-2). ISO 68-1 covers metric screw threads and ISO 68-2 inch screw threads. However, only ISO 68-1 was published as a DIN ISO Standard with the same number. DIN ISO 8488:2
13、016-07 4 National Annex NA (informative) Bibliography DIN ISO 68-1, ISO general purpose metric screw threads Basic profile Part 1: Metric screw threads DIN ISO 965-1, ISO general purpose metric screw threads Tolerances Part 1: Principles and basic data DIN ISO 1502, ISO general purpose metric screw
14、threads Gauges and gauging DIN ISO 6692, Cycles Marking of cycles components DIN ISO 8488:2016-07 5 Cycles Screw threads used to assemble head fittings on bicycle forks 0 Introduction Inch screw threads of BSC (British Standard Cycle) thread profile are used extensively throughout the world for vari
15、ous applications on bicycle components, and have been standardized in national standards. The purpose of this document is to provide an International Standard for the particular screw thread used to assemble the head race and locknut on bicycle forks; it is based on the use of the ISO basic thread p
16、rofile 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 will inevitably take a long time to complete in view of the millions of bicycles now in use which employ BSC thread profile inch screw th
17、reads and for which replacement spare parts will be required. For this reason, in order to minimize changes in production methods during the changeover to the International Standard, and also to secure satisfactory interchangeability with the BSC screw threads now used, the ISO screw thread in this
18、International Standard has the same pitch as that of the 1,000 in 24 t.p.i. BSC screw thread it is intended to replace. An M25,522 1,058 (1,005 in 24 t.p.i.) screw thread of ISO basic profile has been adopted in this International Standard. The basic pitch diameter of this thread is identical to the
19、 1,000 in 24 t.p.i. BSC thread, but, due to the smaller crest truncation of the ISO profile (see figure 1), interference may occur at the major diameter when an ISO fork thread made towards its upper limit is assembled with a BSC race/locknut thread made towards its lower limit on major diameter. Th
20、e possibility of interference occurring in this manner is considered to be unlikely in practice because of the effect of the manufacturing tolerances ( ve on the fork and + ve on the fittings) and the usual practice of using high-crested screwing taps. However, a practical investigation has been car
21、ried out and has confirmed that there is little possibility of any interference arising in practice. NOTE In addition to the 1.000 in 24 t.p.i. BSC thread referred to above, it should particularly be noted that there exists in the cycle trade other widely used threads: French 25 mm 1,0 mm (0,984 in
22、25.4 t.p.i.) Italian 25,4 mm 1,058 mm (1 in 24 t.p.i.) UK 25,4 mm 0,977 mm (1 in 26 t.p.i.) USA 25,4 mm 1,058 mm (1 in 24 t.p.i.) The French and UK threads are clearly not interchangeable with the BSC thread due to outside diameter and t.p.i. respectively. The Italian thread is also not compatible d
23、ue to the Italian flank angle of 55 compared to the BSC angle of 60. As referred to in the second paragraph above, this ISO system of screw threads is intended to replace the 1,000 in 24 t. p. i. BSC threading, but the continued usage of the other noncompatible threadings is not in harmony with the
24、objects of ISO worldwide standardization, and wherever and as soon as possible, it is strongly recommended that all new products change over to the new ISO threads detailed herein. lt should also be noted that where the design size of the fork column tube is already 25,4 mm (1,000 in) nominal, the t
25、hread cutting of this new ISO thread will increase the truncation and facilitate assembly. Attention should be paid to ISO 6692 for the proposals on thread identification marking. DIN ISO 8488:2016-07 6 1 Scope and field of application This International Standard specifies details of the screw threa
26、ds used to assemble head races and locknuts, i.e. fittings, on bicycle fork steering columns. The basic thread profile is that of ISO 68; the tolerance grades and tolerance positions are in accordance with ISO 965/1; the gauging system is that specified in ISO 1502. Threads to this International Sta
27、ndard are interchangeable with the corresponding BSC (British Standard Cycle) thread. 2 References ISO 68, ISO general purpose screw threads Basic profileN1)ISO 965-1, ISO general purpose metric screw threads Tolerances Part 1: Principles and basic data ISO 1502, ISO general purpose metric screw thr
28、eads GaugingN2)ISO 6692, Cycles Marking of cycle components 3 Basic ISO thread profile and basic sizes 3.1 Basic profile The basic profile is that given in ISO 68 and is shown in figure 1. lt is the theoretical profile associated with the basic sizes of the major, pitch and minor diameters of the sc
29、rew 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. 4 Limits and tolerances 4.1 Fundamental deviations and maximum material limits The fundamental deviations are applied to the basic diameters and esta
30、blish the maximum material limits. For the fork thread the fundamental (upper) deviations are negative and correspond to tolerance position “g“ on the major, pitch and minor diameters. For the fittings thread the fundamental (lower) deviations are zero and correspond to tolerance position “H“ on the
31、 major, pitch and minor diameters. N1) National footnote: This standard was withdrawn in 1998 and replaced by ISO 68-1 and ISO 68-2 with deviating titles. N2) National footnote: This standard was replaced in 1996 by a revised version with modified title. The title of the currently valid version of I
32、SO 1502 is ISO general-purpose metric screw threads Gauges and gauging. DIN ISO 8488:2016-07 7 4.2 Tolerance grades, tolerances and limits of size The application of tolerances to the maximum material limits, negative tolerances for the fork thread, and positive tolerances for the fittings thread, d
33、etermines the minimum material limits of size. The tolerances and limits of size are given in tables 2 and 3 respectively for the fork and the fittings. The tolerances are grade 6 in accordance with ISO 965/1. The fundamental deviations and tolerance zones are shown in figure 2. 5 Designation Screw
34、threads made to this International Standard are designated by: a) the nominal diameter of the thread in inch units; b) the pitch of the thread in t.p.i.; c) the tolerance classes of the fittings and fork respectively. Example 1,005 24 6H/6g 6 Gauging system The gauging system is that laid down in IS
35、O 1502 to which reference should be made for details of the thread profiles of the screw gauges and the method of application of the gauges. ISO 1502 gives formulae for the calculation of the gauge limits. These formulae have been used to calculate the gauge limits for the fittings and fork in this
36、International Standard, and these limits are given in tables 4 to 7. lt should be noted that the pitch diameter limits given in tables 4 to 6 relate to the simple pitch diameter, and separate tolerances are given in ISO 1502 for the pitch and flank angles of these gauges. These tolerances are: Pitch
37、 tolerance = 0,005 mm Flank angle tolerance = 15 for profiles with complete flanksN3)= 16 for profiles with truncated flanks Table 1 Basic dimensions Nominal diameter of thread in t.p.i. Basic sizes, mm Major diameter Pitch diameter Minor diameter 1,005 24 25,522 24,836 24,379 N3) National footnote:
38、 The character “ ” denotes the unit “inch” (see National foreword). DIN ISO 8488:2016-07 8 Table 2 Limits and tolerances for screw threads on the fork t.p.i. Major diameter, d mm Pitch diameter, d2mm Minor diameter, d1mm max. tol. min. max. tol. min. max. 24 25,496 0,180 25,316 24,810 0,125 24,685 2
39、4,209 1 2 3 4 5 6 7 8 NOTE The tolerances given in columns 3 and 6 are those recommended in ISO 965/1 for the nearest metric pitch corresponding to the t.p.i. given in column 1. Note that the grade 6 pitch diameter tolerance differs from the grade 6 major diameter tolerance. The limit for the maximu
40、m minor diameter corresponds to a truncation of H/6. Table 3 Limits and tolerances for screw threads on fittings t.p.i. Major diameter, D mm Pitch diameter, D2mm Minor diameter, D1mm D3min. D min. max. tol. min. max. tol. min. 24 25,598 25,522 25,006 0,170 24,836 24,615 0,236 24,379 1 2 3 4 5 6 7 8
41、9 NOTE The tolerances given in columns 5 and 8 are those recommended in ISO 965/1 for the nearest metric pitch corresponding to the t.p.i. given in column 1. Note that the grade 6 pitch diameter tolerance differs from the grade 6 minor diameter tolerance. D3min. is the diameter to the radiused root
42、of the fittings thread that just clears the crest of a maximum fork thread, assuming no clearance between the flanks of the assembled threads. DIN ISO 8488:2016-07 9 Table 4 Fork limits of size for GO screw ring and calliper gauges, and associated screw check, wear and setting plugs Dimensions in mi
43、llimetres Type of gauge Major diameter Pitch diameter Minor diameter max. min. max. min. max. min. Solid GO screw ring gauge 25,572 2 24,815 24,801 24,379 24,365 Adjustable GO screw ring gauge 25,572 2 Set on setting plug 24,367 24,363 GO screw calliper gauge Cleared Distance from pitch line to cres
44、t is 0,229 2 GO screw check plug for new solid GO screw ring gauge 25,505 25,487 24,797 24,789 24,056 6 NOT GO screw check plug for new solid GO screw ring gauge 25,033 7 25,019 7 24,819 5 24,810 5 24,384 7 Wear check plug for solid or adjustable GO screw ring gauge 25,041 7 25,027 7 24,827 5 24,818
45、 5 24,386 7 Setting plug for GO screw calliper gauge 25,505 25,487 24,797 24,789 24,056 6 Full profile setting plug for adjustable GO screw ring gauge 25,505 25,487 24,808 24,800 24,056 6 Truncated profile setting plug for adjustable GO screw ring gauge 25,022 2 25,008 2 24,808 24,800 24,056 6 Table
46、 5 Fork Limits of size for NOT GO screw ring and calliper gauges, and associated screw check, wear and setting plugs Dimensions in millimetres Type of gauge Major diameter Pitch diameter Minor diameter max. min. max. min. max. min. Solid NOT GO screw ring gauge cleared 24,896 7 24,685 24,671 24,473
47、3 24,445 3 Adjustable NOT GO screw ring gauge cleared 24,896 7 Set on setting plug 24,473 3 24,445 3 NOT GO screw calliper gauge Thread profile sizes as for NOT GO screw ring gauge GO screw check plug for new solid NOT GO screw ring gauge 25,380 25,362 24,667 24,659 24,056 6 NOT GO screw check plug
48、for new solid NOT GO screw ring gauge 25,380 25,362 24,689 5 24,680 5 24,056 6 Wear check plug for solid or adjustable NOT GO screw ring gauge 25,385 25,367 24,694 5 24,685 5 24,056 6 Setting plug for NOT GO screw calliper gauge 25,373 25,355 24,678 24,670 24,056 6 Full profile setting plug for adju
49、stable NOT GO screw ring gauge 25,373 25,355 24,678 24,670 24,056 6 Truncated profile setting plug for adjustable NOT GO screw ring gauge 25,105 8 25,087 8 24,678 24,670 24,056 6 DIN ISO 8488:2016-07 10 Table 6 Fittings Limits of size for GO and NOT GO screw plug gauges Dimensions in millimetres Type of gauge Major diameter Pitch diameter Minor diameter New gauge Worn gauge max. min. max. min. min. max. GO screw plug gauge 25,545 25,523 24,853 5 24,842 5
