1、BSI Standards PublicationBS ISO 3302-1:2014Rubber Tolerances forproductsPart 1: Dimensional tolerancesBS ISO 3302-1:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 3302-1:2014. Itsupersedes BS 3734-1:1997 which is withdrawn.The UK participation in its prep
2、aration was entrusted to TechnicalCommittee PRI/73, Industrial rubber products.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correc
3、tapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 81957 5ICS 83.140.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy C
4、ommittee on 31 July 2014.Amendments issued since publicationDate Text affectedBS ISO 3302-1:2014 ISO 2014Rubber Tolerances for products Part 1: Dimensional tolerancesCaoutchouc Tolrances pour produits Partie 1: Tolrances dimensionnellesINTERNATIONAL STANDARDISO3302-1Second edition2014-07-15Reference
5、 numberISO 3302-1:2014(E)BS ISO 3302-1:2014ISO 3302-1:2014(E)ii ISO 2014 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2014All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical,
6、 including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax +
7、41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 3302-1:2014ISO 3302-1:2014(E) ISO 2014 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Measurement of dimensions 13.1 General . 13.2 Test instruments 24 Tolerances .
8、25 Mouldings 25.1 General . 25.2 Classification . 35.3 Fixed dimensions and closure dimensions . 35.4 Tolerances . 35.5 Flash . 56 Extrusions 56.1 General . 56.2 Classification . 66.3 Tolerances . 67 Calendered sheet 97.1 General . 97.2 Classification 107.3 Tolerances 10BS ISO 3302-1:2014ISO 3302-1:
9、2014(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for whi
10、ch a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all m
11、atters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This
12、document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or al
13、l such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users an
14、d does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary in
15、formationThe committee responsible for this document is ISO/TC 45, Rubber and rubber products, Subcommittee SC 4, Products (other than hoses).This second edition cancels and replaces the first edition (ISO 3302-1:1996), which has been technically revised to incorporate the Amendment ISO 3302-2:1996/
16、Amd.1:2001.ISO 3302 consists of the following parts, under the general title Rubber Tolerances for products: Part 1: Dimensional tolerances Part 2: Geometrical tolerancesiv ISO 2014 All rights reservedBS ISO 3302-1:2014ISO 3302-1:2014(E)IntroductionRubber products are subject to changes in their dim
17、ensions after processing and vulcanization. This can be due to a variety of factors, such as mould shrinkage or relaxation of die swell.These 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 clas
18、ses outlined in this specification are not to be demanded unless required by the final application and are to be restricted to those dimensions deemed to be critical. The greater the degree of accuracy demanded, the closer the control to be be exercised during manufacture, and hence the higher the c
19、osts.When particular physical properties are required in the product, it might not always be possible to provide them in a mix which is capable of fabrication to close tolerances. lt is advisable, in these circumstances, that consultation should take place between the interested parties. In general,
20、 softer vulcanizates (i.e. those of hardness below 50 IRHD - see ISO 48) need greater tolerances than harder ones. ISO 2014 All rights reserved vBS ISO 3302-1:2014BS ISO 3302-1:2014Rubber Tolerances for products Part 1: Dimensional tolerances1 ScopeThis part of ISO 3302 specifies classes of dimensio
21、nal tolerances and their values for moulded, extruded, and calendared solid rubber products. The relevant test methods necessary for the establishment of compliance with this part of ISO 3302 are also specified.The tolerances are primarily intended for use with vulcanized rubber but can also be suit
22、able for products made of thermoplastic rubbers.This part of ISO 3302 does not apply to precision toroidal sealing rings or to calendared composite products such as rubber-coated fabrics or products where a rubber coating is applied by the process of topping or skim coating.2 Normative referencesThe
23、 following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 3, Pref
24、erred numbers Series of preferred numbersISO 48, Rubber, vulcanized or thermoplastic Determination of hardness (hardness between 10 IRHD and 100 IRHD)ISO 2230, Rubber products Guidelines for storageISO 23529, Rubber General procedures for preparing and conditioning test pieces for physical test meth
25、ods3 Measurement of dimensions3.1 GeneralFor solid products, measurements of dimensions shall not be made until 16 h have elapsed after vulcanization, this minimum time is being extended to 72 h in cases of dispute. Measurements shall be completed within 3 months after the date of despatch to the pu
26、rchaser or before the product is put into use, whichever is the shorter time. Measurements shall be made at standard temperature, after conditioning, in accordance with ISO 23529. Care shall be taken to ensure that the products are not subjected to adverse storage conditions in accordance with ISO 2
27、230, and that they are not distorted during measurement.INTERNATIONAL STANDARD ISO 3302-1:2014(E) ISO 2014 All rights reserved 1BS ISO 3302-1:2014ISO 3302-1:2014(E)3.2 Test instruments3.2.1 Depending on the circumstances, measurements shall be made using one or more of the following types of instrum
28、ent.3.2.1.1 For solid products, a micrometre dial gauge, the foot of which shall exert a pressure of 22 kPa 5 kPa for rubber of hardness equal to or greater than 35 IRHD or of 10 kPa 2 kPa for rubber of hardness less than 35 IRHD as specified in ISO 23529 and ISO 48.3.2.1.2 A suitable optical measur
29、ing instrument.3.2.1.3 Fixed gauges, for upper and lower limits appropriate to the dimensions being measured.3.2.1.4 Other devices, including tape measures (with or without vernier), sliding calipers, and micrometre calipers.3.2.2 All instruments shall be capable of measuring the dimension with an e
30、rror within the tolerances specified.3.2.3 In all measurements intended to be comparative, the same measuring device shall be used.4 TolerancesFor the purposes of this part of ISO 3302, nominal dimensions and tolerances are based on the R 5 and R 10 series of preferred numbers, respectively, in acco
31、rdance with ISO 3.The dimensions of certain parameters of a particular product may not all require the application of the same class of tolerance. Dimensions of different parameters of the product on the same drawing can have different class tolerances applied to them. When drawings do not indicate
32、a class tolerance, the largest tolerance given in the related table shall be applied.NOTE 1 Tolerances that are specified in this part of ISO 3302 in terms of a positive value and an equal negative value (e.g. 0,35) can also be expressed in terms of unequal positive and negative values, providing th
33、e difference between the two values remains the same. For example, 0,35 may also be expressed as+0502,or 007+ ,or 070,etc.NOTE 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 Mouldings5.
34、1 GeneralThe dimensional tolerances stated in this part of ISO 3302 may be wider than those used in some other engineering practice. The following considerations apply.a) All rubber shows some shrinkage when cooled after moulding, and for this is made in the mould design. The amount of shrinkage is
35、dependent on the rubber type and the mix used, but also varies from batch to batch of the same mix. Products made from some silicone rubbers, fluorocarbon elastomers, and other special-purpose elastomers are subject to larger shrinkages; therefore, tolerance classes M1 and M2 (see 5.2) are very diff
36、icult to obtain with these rubbers.b) Non-rubber parts bonded to the rubber will affect the shrinkage and, therefore, the practicable tolerances.2 ISO 2014 All rights reservedBS ISO 3302-1:2014ISO 3302-1:2014(E)c) Moulds are made in various ways depending on the type of product and accuracy demanded
37、. In general, product can be no more accurate than the mould, and the greater the degree of accuracy demanded, the more expensive the moulds and their maintenance become.d) Care shall be taken in applying the standard tolerances to products having wide sectional variations.e) In cases where the rubb
38、er product is unavoidably distorted during removal from the mould, the dimensions of the products can be affected, and special allowance might be needed.5.2 ClassificationThis subclause establishes four classes of tolerance for fixed and closure dimensions (see 5.3) for products moulded in solid rub
39、ber.a) Class M1 for precision mouldings. Such mouldings require precision moulds, fewer cavities per mould, close mix controls, etc., which results in high cost. Optical comparators or other, similar, measuring devices might be required to minimize distortion of the rubber by the measuring instrumen
40、t. This type of part requires expensive control and inspection procedures.b) Class M2 for high-quality mouldings involving much of the close control required for class M1.c) Class M3 for good-quality mouldings.d) Class M4 for mouldings where dimensional control is non-critical.A classification syste
41、m for flash is given in 5.5.5.3 Fixed dimensions and closure dimensionsIn moulding a rubber product, more rubber is used than is required to fill the cavity, and the excess is flashed. This flash tends to prevent the mould sections from fully closing and, thus, affects the finished part dimensions.N
42、OTE 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 defined below.5.3.1 Fixed dimensions (F): Dimensions which are not affected by deforming influences like flash thickness or lateral displacement of d
43、ifferent mould parts (upper and lower parts or cores). See Figure 1, dimensions l1, l2, and l3.5.3.2 Closure dimensions (C): Dimensions which can be altered by variation in the flash thickness or lateral displacement of different mould parts. See Figure 1, dimensions d1, d2, d3, and h.NOTE The dimen
44、sions for F and C can only be tolerance insofar as they are independent of each other.5.4 TolerancesThe tolerances to be applied shall be chosen, by agreement between the interested parties, from the classes of tolerance described in 5.2.Standard tolerances are given in Table 1. Fixed tolerances (F)
45、 are related by size to each dimension, but all closure tolerances (C) are determined by the largest closure dimension (h, see Figure 1). ISO 2014 All rights reserved 3BS ISO 3302-1:2014ISO 3302-1:2014(E)Xhdddlll1123322341KeyX direction of pressure1 upper half of mould2 moulded part3 flash4 lower ha
46、lf of mouldFigure 1 Compression mould and moulded part (diagrammatic)4 ISO 2014 All rights reservedBS ISO 3302-1:2014ISO 3302-1:2014(E)Table 1 Tolerances for mouldingsDimensions in millimetres (unless indicated otherwise)Nominal dimension Class M1 Class M2 Class M3 Class M4Aboveup to and includingF
47、C F C F C F and C 0 4,0 0,08 0,10 0,10 0,150,25 0,40 0,504,0 6,3 0,10 0,12 0,15 0,206,3 10 0,10 0,15 0,20 0,20 0,30 0,50 0,7010 16 0,15 0,20 0,20 0,25 0.40 0,60 0,8016 25 0,20 0,20 0,25 0,35 0,50 0,80 1,0025 40 0,20 0,25 0,35 0,40 0,60 1,00 1,3040 63 0,25 0,35 0.40 0,50 0,80 1,30 1,6063 100 0,35 0,4
48、0 0,50 0,70 1,00 1,60 2,00100 160 0,40 0,50 0,70 0,80 1,30 2,00 2,50160 0,3 % 0,4 % 0,5 % 0,7 % 0,8 % 1,3 % 1,5 %5.5 FlashThis subclause establishes 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
49、Accurate flashX3 1,0 Normal flashX4 2,0 Rough flashX5 No limit Non-criticalaClass X0 can only apply to those surfaces of an article which do not have parting lines.6 Extrusions6.1 GeneralExtruded rubber products require greater tolerances in manufacture than those produced by moulding since the rubber undergoes die swell and, during subsequent vulcanization, shrinkage and deformation usually occur.Deformation can be reduced by the use of supports during vulcanization, the nature of the support dependin
