IEC 61631:2020

IEC 61631 ®
Edition 2.0 2020-05
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Test method for the mechanical strength of cores made of magnetic oxides
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The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

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IEC 61631 ®
Edition 2.0 2020-05
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Test method for the mechanical strength of cores made of magnetic oxides

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.100.10 ISBN 978-2-8322-8343-1

– 2 – IEC 61631:2020 RLV © IEC 2020
CONTENTS
FOREWORD . 3
INTRODUCTION . 2
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Apparatus . 7
4.1 Test core support and loading wedge . 7
4.2 Testing device . 7
4.3 Humidity measuring device . 7
5 Test cores . 7
5.1 General . 7
5.2 Number of test cores . 7
5.3 Precautions . 7
6 Testing . 8
6.1 Test conditions . 8
6.2 Test procedures . 8
6.2.1 General . 8
6.2.2 Test of E-cores . 8
6.2.3 I-test Test of I-cores . 10
6.2.4 Test of ring-cores . 11
Annex A (normative) Standard dimensions of E-cores and their support
for strength test . 13
A.1 Introduction General . 13
A.2 Designation . 13
A.3 Test core support . 13
Annex B (normative) Standard dimensions of ring-cores and methods for strength test . 16
B.1 General . 16
B.2 Selection of mechanical strength test method for ring-core . 16
Bibliography . 17

Figure 1 – E test . 9
Figure 2 – W test . 9
Figure 3 – T test . 10
Figure 4 – M test . 10
Figure 5 – I test . 11
Figure 6 – Stretching method . 11
Figure 7 –Shearing method . 12
Figure 8 – Pressure method . 12
Figure A.1 – Designation of E-core . 13
Figure B.1 – Dimensions of ring-core . 16

Table A.1 – Test core support . 14
Table B.1 – Ring-core dimension designations . 16

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
TEST METHOD FOR THE MECHANICAL STRENGTH
OF CORES MADE OF MAGNETIC OXIDES

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC
Publication(s)"). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This redline version of the official IEC Standard allows the user to identify the changes
made to the previous edition. A vertical bar appears in the margin wherever a change
has been made. Additions are in green text, deletions are in strikethrough red text.

– 4 – IEC 61631:2020 RLV © IEC 2020
International Standard IEC 61631 has been prepared by IEC technical committee 51:
Magnetic components, ferrite and magnetic powder materials.
This second edition cancels and replaces the first edition published in 2001. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the phrase: "This document is also applicable to the mechanical strength measurement of
magnetic powder cores" has been added in the scope;
b) IEC 61246 has been replaced by IEC 63093-8; EN 1002-2 has been replaced by
ISO 7500-1; ISO 4677-1 and ISO 4677-2 have been withdrawn;
c) dimensions D and F in Figure A.1 and Table A.1 have been changed to be consistent with
Figure 1 of IEC 63093-8:2018;
d) addition of the content of ring-cores test;
e) addition of Annex B;
f) the location of the jig is amended in Figure 3;
g) in Figure 5, the roller bars are moved to the edge of the I-core, aligned with the core.
The text of this International Standard is based on the following documents:
CDV Report on voting
51/1312/CDV 51/1333/RVC
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
INTRODUCTION
The method specified in this document is intended to be used for obtaining agreements
between parties for material development, quality checking, characterization and data
acquisition purposes. The method places closely defined restrictions on the arrangement of
the test-piece and the function of the test apparatus, including the test-jigs, in order to
minimize the errors that can arise as a consequence of the test method.
All other factors are required to be stated in the test report in order to be allowed for in the
com
...

IEC 61631 ®
Edition 2.0 2020-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Test method for the mechanical strength of cores made of magnetic oxides

Méthode d'essai pour la résistance mécanique des noyaux en oxydes
magnétiques
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

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et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
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les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and
once a month by email. French extracted from the Terms and Definitions clause of
IEC publications issued since 2002. Some entries have been
IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and
If you wish to give us your feedback on this publication or CISPR.

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IEC 61631 ®
Edition 2.0 2020-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Test method for the mechanical strength of cores made of magnetic oxides

Méthode d'essai pour la résistance mécanique des noyaux en oxydes

magnétiques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.100.10 ISBN 978-2-8322-9051-4

– 2 – IEC 61631:2020 © IEC 2020
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Apparatus . 6
4.1 Test core support and loading wedge . 6
4.2 Testing device . 7
4.3 Humidity measuring device . 7
5 Test cores . 7
5.1 General . 7
5.2 Number of test cores . 7
5.3 Precautions . 7
6 Testing . 7
6.1 Test conditions . 7
6.2 Test procedures . 7
6.2.1 General . 7
6.2.2 Test of E-cores . 8
6.2.3 Test of I-cores . 10
6.2.4 Test of ring-cores . 10
Annex A (normative) Standard dimensions of E-cores and their support
for strength test . 13
A.1 General . 13
A.2 Designation . 13
A.3 Test core support . 13
Annex B (normative) Standard dimensions of ring-cores and methods for strength test . 15
B.1 General . 15
B.2 Selection of mechanical strength test method for ring-core . 15
Bibliography . 16

Figure 1 – E test . 8
Figure 2 – W test . 9
Figure 3 – T test . 9
Figure 4 – M test . 10
Figure 5 – I test . 10
Figure 6 – Stretching method . 11
Figure 7 – Shearing method . 12
Figure 8 – Pressure method . 12
Figure A.1 – Designation of E-core . 13
Figure B.1 – Dimensions of ring-core . 15

Table A.1 – Test core support . 14
Table B.1 – Ring-core dimension designations . 15

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
TEST METHOD FOR THE MECHANICAL STRENGTH
OF CORES MADE OF MAGNETIC OXIDES

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC
Publication(s)"). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61631 has been prepared by IEC technical committee 51:
Magnetic components, ferrite and magnetic powder materials.
This second edition cancels and replaces the first edition published in 2001. This edition
...