1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ICS 83.140.01 ISBN 0-626-14304-7 SANS 3302-1:2003 Edition 1 and ISO amdt 1 ISO 3302-1:1996 Edition 1 and amdt 1 SOUTH AFRICAN NATIONAL STANDARD Rubber To
4、lerances for products Part 1: Dimensional tolerances This national standard is the identical implementation of ISO 3302-1:1996 and amendment 1, and is adopted with the permission of the International Organization for Standardization. Published by Standards South Africa 1 dr lategan road groenkloof p
5、rivate bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa 2003 SANS 3302-1:2003 Edition 1 and ISO amdt 1 ISO 3302-1:1996 Edition 1 and amdt 1 Table of changes Change No. Date Scope ISO amdt 1 2001-06-01 Amended to add a class
6、ification system for flash. National foreword This South African standard was approved by National Committee STANSA TC 5140.17, Rubber and rubber products, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. Reference numberISO 3302-1:1996/Am
7、d.1:2001(E)ISO 2001INTERNATIONALSTANDARDISO3302-1First edition1996-07-15AMENDMENT 12001-06-01Rubber Tolerances for products Part 1:Dimensional tolerancesAMENDMENT 1: Classification system forflashCaoutchouc Tolrances pour produits Partie 1: Tolrances dimensionnellesAMENDEMENT 1: Systme de classifica
8、tion des bavuresISO 3302-1:1996/Amd.1:2001(E) ISO 2001 All rights reserved iiiForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISOmember bodies). The work of preparing International Standards is normally carried out through ISO
9、technicalcommittees. Each member body interested in a subject for which a technical committee has been established hasthe right to be represented on that committee. International organizations, governmental and non-governmental, inliaison with ISO, also take part in the work. ISO collaborates closel
10、y with the International ElectrotechnicalCommission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.Draft International Standards adopted by the technical committees are circulated to th
11、e member bodies for voting.Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this Amendment may be the subject of patentrights. ISO shall not be held responsible for ident
12、ifying any or all such patent rights.Amendment 1 to International Standard ISO 3302-1:1996 was prepared by Technical Committee ISO/TC 45,Rubber and rubber products, Subcommittee SC 4, Products (other than hoses).ISO 3302-1:1996/Amd.1:2001(E) ISO 2001 All rights reserved 1Rubber Tolerances for produc
13、ts Part 1:Dimensional tolerancesAMENDMENT 1: Classification system for flashPage 3, end of subclause 5.2Add the following paragraph:“A classification system for flash is given in 5.5.”Page 4, immediately before the beginning of clause 6Add the following subclause:5.5 FlashThis subclause establishes
14、six classes of flash, as listed in Table 2.Table 2 Classes of flashClassMaximum height of flashmmDescriptionX0 0 No flashaX1 0,1 Precision flashX2 0,5 Accurate flashX3 1 Normal flashX4 2 Rough flashX5 No limit Non-criticalaClass X0 can only apply to those surfaces of an article which do not have par
15、ting lines.RenumberingRenumber existing Tables 2 to 9 as Tables 3 to 10.This page is intentionally left blankINTERNATIONAL STANDARD IS0 3302-I First edition 1996-07-15 Rubber - Tolerances for products - Part 1: Dimensional tolerances Caoutchouc - Tolkances pour produits - Par-tie I: ToMrances dimens
16、ionnelles Reference number IS0 3302-1:1996(E) IS0 33024:1996(E) Foreword IS0 (the International Organization for Standardization) is a worldwide fed- eration of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical
17、committees. Each member body interested in a subject for which a technical committee has been established has the right to be rep- resented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. IS0 col- laborates closely w
18、ith the International Electrotechnical Commission (I EC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are cir- culated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 %
19、 of the member bodies casting a vote. International Standard IS0 3302-I was prepared by Technical Committee lSO/TC 45, Rubber and rubber products, Subcommittee SC 4, Miscel- laneous products. This edition of IS0 3302-I cancels and replaces IS0 3302:1990, Rubber - Dimensional tolerances for use with
20、products, of which it constitutes a technical revision, in particular in relation to table 1 (tolerances for mould- ings). IS0 3302 consists of the following parts, under the general title Rubber - Tolerances for products: Part 7: Dimensional tolerances Part 2: Geometrical tolerances 0 IS0 1996 All
21、rights reserved. Unless otherwise specified, no part of this publication may be repro- duced or utilized in any form or by any means, electronic or mechanical, including photo- copying and microfilm, without permission in writing from the publisher. International Organization for Standardization Cas
22、e Postale 56 l CH-1211 Geneve 20 l Switzerland Printed in Switzerland II IS0 IS0 3302=1:1996(E) Introduction Rubber products are subject to changes in their dimensions after process- ing and vulcanization. This may be due to a variety of factors, such as mould shrinkage or relaxation of die swell. T
23、hese changes should be determined and allowed for when designing such items as moulds and dies used in the manufacture of a given product. The closer tolerance classes outlined in this specification should not be demanded unless required by the final application and should be restricted to those dim
24、ensions deemed to be critical. The greater the degree of ac- curacy demanded, the closer the control which must be exercised during manufacture, and hence the higher the costs. When particular physical properties are required in the product, it may not always be possible to provide them in a mix whi
25、ch is capable of fabrication to close tolerances. It is advisable, in these circumstances, that consul- tation should take place between the interested parties. In general, softer vulcanizates (i.e. those of hardness below 50 IRHD - see IS0 48) need greater tolerances than harder ones. This page is
26、intentionally left blankINTERNATIONAL STANDARD IS0 IS0 3302=1:1996(E) Rubber - Tolerances for products - Part 1: Dimensional tolerances 1 Scope This part of IS0 3302 specifies classes of dimensional tolerances, and their values, for moulded, extruded and calendered solid rubber products. The relevan
27、t test methods necessary for the establishment of compliance with this International Standard are also specified. The tolerances are primarily intended for use with vul- canized rubber but may also be suitable for products made of thermoplastic rubbers. This part of IS0 3302 does not apply to precis
28、ion to- roidal sealing rings or to calendered composite prod- ucts such as rubber-coated fabrics or products where a rubber coating is applied by the process of topping or skim coating. 2 Normative references The following standards contain provisions which, through reference in this text, constitut
29、e provisions of this part of IS0 3302. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of IS0 3302 are encouraged to investigate the possibility of applying the most recent editions of the standards li
30、sted below. Members of IEC and IS0 maintain registers of currently valid International Stan- dards. IS0 3:1973, Preferred numbers - Series of preferred numbers. IS0 48: 1994, Rubber, vulcanized or thermoplastic - Determination of hardness (hardness between 10 IRHD and 100 IRHD). IS0 471 :I 995, Rubb
31、er - Temperatures, humidities and times for conditioning and testing. IS0 2230: 1973, Vulcanized rubber - Guide to stor- age. IS0 4648: 1991, Rubber, vulcanized or thermoplas- tic - Determination of dimensions of test pieces and products for test purposes. 3 Measurement of dimensions 3.1 General For
32、 solid products, measurements of dimensions shall not be made until 16 h have elapsed after vulcaniz- ation, this minimum time being extended to 72 h in cases of dispute. Measurements shall be completed within 3 months after the date of despatch to the pur- chaser or before the product is put into u
33、se, which- ever is the shorter time. Measurements shall be made at standard temperature, after conditioning (see IS0 471). Care shall be taken to ensure that the prod- ucts are not subjected to adverse storage conditions (see IS0 2230) and that they are not distorted during measurement. IS0 3302=1:1
34、996(E) IS0 3.2 Test instruments 5 Mouldings 3.2.1 Depending on the circumstances, measure- ments shall be made using one or more of the follow- ing types of instrument: 3.2.1.1 For solid products, a micrometer dial gauge, the foot of which shall exert a pressure of 22 kPa + 5 kPa for rubber of hardn
35、ess equal to or greater than 35 IRHD or of 10 kPa + 2 kPa for rubber of hardness less than 35 IRHD (see IS0 4648 and IS0 48). 3.2.1.2 A suitable optical measuring instrument. 3.2.1.3 Fixed gauges, for upper and lower limits ap- propriate to the dimensions being measured. 3.2.1.4 Other devices, inclu
36、ding tape measures (with or without vernier), sliding calipers and microm- eter calipers. 3.2.2 All instruments shall be capable of measuring the dimension with an error within the tolerances specified. 3.2.3 In all measurements intended to be compara- tive, the same measuring device shall be used.
37、4 Tolerances For the purposes of this part of IS0 3302, nominal di- mensions and tolerances are based on the R 5 and R 10 series of preferred numbers respectively (see IS0 3). The dimensions of certain parameters of a particular product may not all require the application of the same class of tolera
38、nce. Dimensions of different parameters of the product on the same drawing may have differ- ent class tolerances applied to them. When drawings do not indicate a required class tolerance, the largest tolerance given in the related table shall be applied. NOTES 1 Tolerances that are specified in this
39、 part of IS0 3302 in terms of a positive value and an equal negative value (e.g. + 0,35) may also be expressed in terms of unequal positive and negative values, providing the difference between the two values remains t,hOeZ sam+$.7 For+;xample, + 0,35 may also be expressed as -0;5 or -0 or -o,7, etc
40、. 2 Special consideration of tolerances will be necessary for a vulcanizate with a low hardness and a high tensile strength (e.g. natural rubber gum vulcanizate). 5.1 General The dimensional tolerances stated in this part of IS0 3302 may be wider than those used in some other engineering practice. T
41、he following consider- ations apply: a) b) d d) e) All rubber shows some shrinkage when cooled after moulding, and allowance for this is made in the mould design. The amount of shrinkage is de- pendent on the rubber type and the mix used, but also varies from batch to batch of the same mix. Products
42、 made from some silicone rubbers, fluorocarbon elastomers and other special- purpose elastomers are subject to larger shrink- ages; therefore tolerance classes Ml and M2 (see 5.2) are very difficult to obtain with these rubbers. Non-rubber parts bonded to the rubber will affect the shrinkage and, th
43、erefore, the practicable tol- erances. Moulds are made in various ways depending on the type of product and accuracy demanded. In general, the product can be no more accurate than the mould, and the greater the degree of ac- curacy demanded, the more expensive become the moulds and their maintenance
44、. Care shall be taken in applying the standard toler- ances to products having wide sectional vari- ations. In cases where the rubber product is unavoidably distorted during removal from the mould, the di- mensions of the products may be affected, and special allowance may be needed. 5.2 Classificat
45、ion This subclause establishes four classes of tolerance for fixed and closure dimensions (see 5.3) for products moulded in solid rubber, namely: a) Class Ml for precision mouldings. Such mould- ings require precision moulds, fewer cavities per mould, close mix controls, etc., which results in high
46、cost. Optical comparators or other, similar, measuring devices may be required to minimize distortion of the rubber by the measuring instru- ment. This type of part requires expensive control and inspection procedures. b) Class M2 for high-quality mouldings involving much of the close control requir
47、ed for class Ml. 2 IS0 lSO3302-1:1996(E) c) Class M3 for good-quality mouldings. d) Class M4 for mouldings where dimensional con- trol is non-critical. 5.3 Fixed dimensions and closure dimensions In moulding a rubber product, more rubber is used than is required to fill the cavity, and the excess is
48、 flashed. This flash tends to prevent the mould sec- tions from fully closing and thus affects the finished- part dimensions. NOTE 3 For products moulded by transfer or injection, it is possible to regard all dimensions as fixed. Two sets of tolerances, F and C, are given and are de- fined below. 5.
49、3.1 fixed dimensions (F): Dimensions which are not affected by deforming influences like flash thick- ness or lateral displacement of different mould parts (upper and lower parts or cores). See figure 1, dimen- sions II, 22 and 13. 5.3.2 closure dimensions (C): Dimensions which can be altered by variation in the flash thickness or lateral displacement of different mould parts. See fig- ure 1, dimensions dl, d2, d3 and h. NOTE 4 The dimensions for F and C can only be toler- anced insofar as they are independent of each other. 5.4 Tolerances The tolerances to b
