EN ISO 642:2024

SLOVENSKI STANDARD
01-november-2024
Jeklo - Preskus kaljivosti jekla po Jominyju (ISO 642:2024)
Steel - Hardenability test by end quenching (Jominy test) (ISO 642:2024)
Stahl - Stirnabschreckversuch (Jominy-Versuch) (ISO 642:2024)
Acier - Essai de trempabilité par trempe en bout (essai Jominy) (ISO 642:2024)
Ta slovenski standard je istoveten z: EN ISO 642:2024
ICS:
77.040.99 Druge metode za Other methods of testing of
preskušanje kovin metals
77.080.20 Jekla Steels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 642
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2024
EUROPÄISCHE NORM
ICS 77.040.99 Supersedes EN ISO 642:1999
English Version
Steel - Hardenability test by end quenching (Jominy test)
(ISO 642:2024)
Acier - Essai de trempabilité par trempe en bout (essai Stahl - Stirnabschreckversuch (Jominy-Versuch) (ISO
Jominy) (ISO 642:2024) 642:2024)
This European Standard was approved by CEN on 31 August 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 642:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 642:2024) has been prepared by Technical Committee ISO/TC 17 "Steel" in
collaboration with Technical Committee CEN/TC 459/SC 1 “Test methods for steel (other than chemical
analysis)” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2025, and conflicting national standards shall
be withdrawn at the latest by March 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 642:1999.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 642:2024 has been approved by CEN as EN ISO 642:2024 without any modification.

International
Standard
ISO 642
Third edition
Steel — Hardenability test by end
2024-08
quenching (Jominy test)
Acier — Essai de trempabilité par trempe en bout (essai Jominy)
Reference number
ISO 642:2024(en) © ISO 2024
ISO 642:2024(en)
© ISO 2024
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: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 642:2024(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and designations . 1
5 Principle . 2
6 Form of test pieces and their preparation . 2
6.1 Sampling .2
6.2 Dimensions .3
6.3 Heat treatment.4
6.4 Machining .4
7 Apparatus . 4
8 Heating and quenching of test piece . 6
8.1 Heating.6
8.2 Quenching .6
9 Measurement of hardness after quenching . 7
10 Expression of results . 8
10.1 Hardness at any one point .8
10.2 Drawing of the hardness curves .8
10.3 Description of the hardenability characteristics of a particular steel .9
10.4 Codification of test result . .9
11 Test report . 10
Annex A (informative) Specification for the hardenability of a product .11
Annex B (informative) Additional information to Clause 11 .15
Annex C (informative) Computational methods for determination of hardenability .18
Bibliography . 19

iii
ISO 642:2024(en)
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of 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 www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 7, Methods of
testing (other than mechanical tests and chemical analysis), in collaboration with the European Committee
for Standardization (CEN) Technical Committee CEN/TC 459, ECISS - European Committee for Iron and Steel
Standardization, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
This third edition cancels and replaces the second edition (ISO 642:1999), which has been technically
revised.
The main changes are as follows:
— updated the normative references;
— added a new symbol, Jd, in Table 1;
— minimum recommended reduction ratio of 5:1, see 6.1;
— revised the test piece dimensions, see 6.1, 6.2 and Figures 1 and 2;
— revised the heat treatment requirements, see 6.3;
— revised configuration of fixing and centring device, see 7.3 and Figure 3;
— revised text concerning water temperature, see 7.4;
— revised requirement for nitric acid solution concentration, see 9.2;
— revised codification of test result, see 10.4 and Figure 6;
— revised A.2 and Figures A.2 and A.3;
— revised Annex C and Bibliography;
— editorial clarifications;
iv
ISO 642:2024(en)
— reduced the number of bibliographical references.
Any feedback or questio
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