IEC 60404-8-1:2023

IEC 60404-8-1 ®
Edition 4.0 2023-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Magnetic materials –
Part 8-1: Specifications for individual materials – Permanent magnet
(magnetically hard) materials
Matériaux magnétiques –
Partie 8-1: Spécifications pour matériaux particuliers – Matériaux (magnétiques
durs) pour aimants permanents
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.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie 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
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Secretariat 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 IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always have
committee, …). It also gives information on projects, replaced access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and once
and French, with equivalent terms in 19 additional languages.
a month by email.
Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc

If you wish to give us your feedback on this publication or need
further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC -  IEC Products & Services Portal - products.iec.ch
webstore.iec.ch/advsearchform Découvrez notre puissant moteur de recherche et consultez
La recherche avancée permet de trouver des publications IEC gratuitement tous les aperçus des publications. Avec un
en utilisant différents critères (numéro de référence, texte, abonnement, vous aurez toujours accès à un contenu à jour
comité d’études, …). Elle donne aussi des informations sur les adapté à vos besoins.
projets et les publications remplacées ou retirées.

Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
Le premier dictionnaire d'électrotechnologie en ligne au monde,
Restez informé sur les nouvelles publications IEC. Just
avec plus de 22 300 articles terminologiques en anglais et en
Published détaille les nouvelles publications parues.
français, ainsi que les termes équivalents dans 19 langues
Disponible en ligne et une fois par mois par email.
additionnelles. Egalement appelé Vocabulaire

Electrotechnique International (IEV) en ligne.
Service Clients - webstore.iec.ch/csc

Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
IEC 60404-8-1 ®
Edition 4.0 2023-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Magnetic materials –
Part 8-1: Specifications for individual materials – Permanent magnet

(magnetically hard) materials
Matériaux magnétiques –
Partie 8-1: Spécifications pour matériaux particuliers – Matériaux (magnétiques

durs) pour aimants permanents
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.20, 29.030 ISBN 978-2-8322-7503-0

– 2 – IEC 60404-8-1:2023 © IEC 2023
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Types of materials and their applications . 9
5 Classification . 9
5.1 General . 9
5.2 Principal magnetic properties . 10
5.3 Additional magnetic properties . 10
6 Chemical composition . 11
7 Densities . 11
8 Designation . 11
9 Mode of shipment and dimensions . 11
10 Testing . 12
10.1 Extent of testing . 12
10.2 Testing methods . 12
11 Grounds for rejection . 12
12 Description of tables of standard properties . 12
12.1 Magnetically hard alloys . 12
12.1.1 Aluminium-nickel-cobalt-iron-titanium alloys (AINiCo) . 12
12.1.2 Chromium-iron-cobalt alloys (CrFeCo) . 13
12.1.3 Iron-cobalt-vanadium-chromium alloys (FeCoVCr) . 14
12.1.4 Rare earth-cobalt alloys (RECo) . 14
12.1.5 Rare earth-iron-boron sintered and hot deformed magnets (REFeB) . 15
12.2 Magnetically hard ceramics (magnetically hard ferrites) . 16
12.2.1 Chemical composition . 16
12.2.2 Manufacturing method . 17
12.2.3 Sub-classification . 17
12.2.4 Magnetic properties and densities . 17
12.2.5 Dimensional tolerances . 17
12.3 Bonded magnetically hard materials (Bonded magnets) . 17
12.3.1 General . 17
12.3.2 Magnet materials . 17
12.3.3 Manufacturing method . 18
12.3.4 Sub-classification . 18
12.3.5 Magnetic properties and densities . 20
12.3.6 Dimensional tolerances . 20
13 Irreversible demagnetization behaviour . 20
13.1 General . 20
13.2 General definition of demagnetization field strength H . 20
D
13.3 Simplified definition of demagnetization field strength H . 21
D
14 Tables 10 to 25 . 23

Annex A (informative) Physical data and mechanical reference values of AINiCo,
CrFeCo, FeCoVCr, SmCo, NdFeB, hard ferrite and SmFeN bonded magnets . 43
Annex B (informative) Grain boundary diffusion (GBD) process for REFeB sintered

magnets . 45
Annex C (informative) Cerium-iron-boron sintered magnets (CeFeB) . 46
Bibliography . 47

Figure 1 – Graphic representation of B(H) and J(H) demagnetization and recoil curves . 21
Figure 2 – Simplified evaluation of B(H) and J(H) demagnetization and recoil curves . 23
Figure B.1 – Example of coercivity gain of GBD processed sintered REFeB magnets in
dependence of the distance to the magnet surface . 45
Figure C.1 – Manufacturing flow chart of CeFeB sintered magnets . 46

Table 1 – Classification of permanent magnet (magnetically hard) materials . 9
and units
Table 2 – Magnetic properties – Symbols . 10
Table 3 – Additional magnetic properties – Symbols and units . 10
Table 4 – Chemical compositions of AlNiCo alloys (% mass fraction) – for information
purposes only . 12
Table 5 – Chemical compositions of CrFeCo alloys (% mass fraction) – for information
purposes only . 13
Table 6 – Chemical compositions of FeCoVCr alloys (% mass fraction) – for
information purposes only . 14
Table 7 – Chemical compositions of RECo alloys (% mass fraction) – for information

purposes only . 15
Table 8 – Chemical compositions of REFeB sintered and hot deformed magnets (%
mass fraction) – for information purposes only . 16
Table 9 – Chemical compositions of REFeN alloys for bonded magnet (% mass
fraction) – for information purposes only . 18
Table 10 – Magnetic properties and densities of AlNiCo magnets . 24
Table 11 – Magnetic properties and densities of CrFeCo and FeCoVCr magnets . 25
Table 12 – Magnetic properties and densities of RECo sintered magnets. 26
Table 13 – Magnetic properties and densities of REFeB sintered magnets . 28
Table 14 – Magnetic properties and densities of REFeB hot deformed magnets . 30
Table 15 – Magnetic properties and densities of hard ferrites. 31
Table 16 – Magnetic properties and densities of isotropic AlNiCo
...