National foreword

This British Standard is the UK implementation of ISO 3302‑1:2014. It supersedes BS 3734‑1:1997 which is withdrawn.

The UK participation in its preparation was entrusted to Technical Committee PRI/73, Industrial rubber products.

A list of organizations represented on this committee can be obtained on request to its secretary.

This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2014.

Foreword

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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 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 all 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 and does not constitute an endorsement.

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The 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/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 tolerances

Introduction

Rubber products are subject to changes in their dimensions 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 classes 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 costs.

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, softer vulcanizates (i.e. those of hardness below 50 IRHD - see ISO 48) need greater tolerances than harder ones.

1 Scope

This part of ISO 3302 specifies classes of dimensional 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 suitable 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 references

3 Measurement of dimensions

3.1 General

3.2 Test instruments

4 Tolerances

5 Mouldings

5.1 General

5.2 Classification

5.3 Fixed dimensions and closure dimensions

5.4 Tolerances

5.5 Flash

6 Extrusions

6.1 General

6.2 Classification

6.3 Tolerances

7 Calendered sheet

7.1 General

7.2 Classification

7.3 Tolerances

BS ISO 3302-1:2014

Rubber. Tolerances for products - Dimensional tolerances

Current, Under Review

Published:

31 Jul 2014