ISO/DIS 6621-3

Internal combustion engines -- Piston rings

Moteurs à combustion interne -- Segments de piston

Standards Content (sample)

DRAFT INTERNATIONAL STANDARD
ISO/DIS 6621-3
ISO/TC 22/SC 34 Secretariat: ANSI
Voting begins on: Voting terminates on:
2019-11-18 2020-02-10
Internal combustion engines — Piston rings —
Part 3:
Material specifications
Moteurs à combustion interne — Segments de piston —
Partie 3: Spécifications des matériaux
ICS: 43.060.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
This document is circulated as received from the committee secretariat.
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 6621-3:2019(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2019
---------------------- Page: 1 ----------------------
ISO/DIS 6621-3:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2019

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, 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 ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/DIS 6621-3:2019(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Mechanical properties .................................................................................................................................................................................... 1

Bibliography ................................................................................................................................................................................................................................ 4

© ISO 2019 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/DIS 6621-3:2019(E)
Foreword

ISO (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 which 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 matters 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 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.

For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following

URL: www .iso .org/iso/foreword .html.

This document was prepared by Technical Committee ISO/TC22, [Road vehicles], Subcommittee SC34,

[Propulsion, powertrain and powertrain fluids].

This third edition cancels and replaces the second edition (ISO 6621-3:2000), which has been technically

revised.
The main changes compared to the previous edition are as follows:
— Material new subclass was added.
A list of all parts in the ISO 6621 series can be found on the ISO website.
iv © ISO 2019 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/DIS 6621-3:2019(E)
Introduction

ISO 6621 is one of a series of International Standards dealing with piston rings for reciprocating

[5] [6] [7] [8]

internal combustion engines. Others are ISO 6622-1 and ISO 6622-2, ISO 6623, ISO 6624-1,

[9] [10] [11] [12] [13] [14] [14]

ISO 6624-2, ISO 6624-3 and ISO 6624-4 , ISO 6625 , ISO 6626 , ISO 6626-2 , ISO 6626-3 ,

[16]
and ISO 6627 .

This part of ISO 6621 provides a user guide to the types of materials available for piston rings.

Many such materials are available, made by different manufacturers using different casting and

machining techniques, with each suited to a particular application. In many instances, their chemical

compositions differ, but the method of manufacture and the heat treatment, if any, result in materials

from different manufacturers with similar mechanical properties. The performance of rings made from

two different materials might be very similar; i.e. several subclasses of materials could meet a given

requirement.

In ring manufacture it is convenient to group materials into classes according to their moduli, since for a

ring of given dimensions, the pressure it exerts on the cylinder wall is determined only by the modulus.

The material strength is also generally related to modulus, i.e. the higher the modulus, the greater the

strength, although there are exceptions depending on the method of manufacture. Material hardness,

on the other hand, is determined by both chemical composition and heat treatment; this is made clear

by the division of classes into subclasses. Because of this, the final choice of material and subclass is to

be agreed between manufacturer and client.
© ISO 2019 – All rights reserved v
----------
...