IEC 60404-8-1:2015

Magnetic materials - Part 8-1: Specifications for individual materials - Magnetically hard materials

IEC 60404-8-1:2015 specifies minimum values for the principal magnetic properties of, and dimensional tolerances for, technically important magnetically hard materials (permanent magnets). For information purposes only, this part of IEC 60404 provides values for the densities of the materials and the ranges of their chemical compositions. Some additional physical data and mechanical reference values concerning the magnetic materials are given for information and comparison purposes. This edition includes the following significant technical changes with respect to the previous edition:
a) recently developed anisotropic Sm-Fe-N bonded magnets are included;
b) high energy ferrites with La and Co as substituents are included.

Matériaux magnétiques - Partie 8-1: Spécifications pour matériaux particuliers - Matériaux magnétiquement durs

L'IEC 60404-8-1:2015 spécifie les valeurs minimales des principales propriétés magnétiques des matériaux magnétiques durs importants d'un point de vue technique (aimants permanents) ainsi que leurs tolérances sur les dimensions. La présente partie de l'IEC 60404 donne uniquement à titre indicatif des valeurs de masses volumiques des matériaux et les plages de leur composition chimique. Dans un but d'information et de comparaison, quelques données physiques et valeurs mécaniques de référence sur les matériaux magnétiques sont aussi données au Tableau A.1. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) elle inclut les aimants agglomérés Sm-Fe-N anisotropes récemment développés;
b) elle inclut les ferrites haute énergie avec les remplaçants La et Co.

General Information

• Status: Published
• Publication Date: 26-Mar-2015
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 17.220.20 - Measurement of electrical and magnetic quantities
• ICS: 29.030 - Magnetic materials
• Technical Committee: TC 68 - Magnetic alloys and steels
• Current Stage: PPUB - Publication issued
• Start Date: 27-Mar-2015
• Completion Date: 27-Mar-2015

Standards Content (sample)

IEC 60404-8-1
Edition 3.0 2015-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Magnetic materials –
Part 8-1: Specifications for individual materials – Magnetically hard materials
Matériaux magnétiques –
Partie 8-1: Spécifications pour matériaux particuliers – Matériaux
magnétiquement durs
IEC 60404-8-1:2015-03(en-fr)
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2015 IEC, Geneva, Switzerland

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 Central Office Tel.: [phone]
3, rue de Varembé Fax: [phone]
CH-1211 Geneva 20 [e-mail]
Switzerland www.iec.ch
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 corrigenda or an amendment might have been published.
IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org

The stand-alone application for consulting the entire The world's leading online dictionary of electronic and

bibliographical information on IEC International Standards, electrical terms containing more than 30 000 terms and

Technical Specifications, Technical Reports and other definitions in English and French, with equivalent terms in 15

documents. Available for PC, Mac OS, Android Tablets and additional languages. Also known as the International

iPad. Electrotechnical Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary

The advanced search enables to find IEC publications by a More than 60 000 electrotechnical terminology entries in

variety of criteria (reference number, text, technical English and French extracted from the Terms and Definitions

committee,…). It also gives information on projects, replaced clause of IEC publications issued since 2002. Some entries

and withdrawn publications. have been collected from earlier publications of IEC TC 37,

77, 86 and CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc

details all new publications released. Available online and If you wish to give us your feedback on this publication or

also once a month by email. need further assistance, please contact the Customer Service

Centre: [e-mail].
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.
Catalogue IEC - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
Application autonome pour consulter tous les renseignements
Le premier dictionnaire en ligne de termes électroniques et
bibliographiques sur les Normes internationales,
électriques. Il contient plus de 30 000 termes et définitions en
Spécifications techniques, Rapports techniques et autres
anglais et en français, ainsi que les termes équivalents dans
documents de l'IEC. Disponible pour PC, Mac OS, tablettes
15 langues additionnelles. Egalement appelé Vocabulaire
Android et iPad.
Electrotechnique International (IEV) en ligne.
Recherche de publications IEC - www.iec.ch/searchpub
Glossaire IEC - std.iec.ch/glossary

La recherche avancée permet de trouver des publications IEC Plus de 60 000 entrées terminologiques électrotechniques, en

en utilisant différents critères (numéro de référence, texte, anglais et en français, extraites des articles Termes et

comité d’études,…). Elle donne aussi des informations sur les Définitions des publications IEC parues depuis 2002. Plus

projets et les publications remplacées ou retirées. certaines entrées antérieures extraites des publications des

CE 37, 77, 86 et CISPR de l'IEC.
IEC Just Published - webstore.iec.ch/justpublished
Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications IEC. Just

Published détaille les nouvelles publications parues. Si vous désirez nous donner des commentaires sur cette

Disponible en ligne et aussi une fois par mois par email. publication ou si vous avez des questions contactez-nous:

[e-mail].
---------------------- Page: 2 ----------------------
IEC 60404-8-1
Edition 3.0 2015-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Magnetic materials –
Part 8-1: Specifications for individual materials – Magnetically hard materials
Matériaux magnétiques –
Partie 8-1: Spécifications pour matériaux particuliers – Matériaux
magnétiquement durs
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.20; 29.030 ISBN 978-2-8322-2429-8

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – IEC 60404-8-1:2015 © IEC 2015
CONTENTS

FOREWORD ......................................................................................................................... 4

INTRODUCTION ................................................................................................................... 6

1 Scope ............................................................................................................................ 7

2 Normative references..................................................................................................... 7

3 Terms and definitions .................................................................................................... 7

4 Types of materials and their applications ........................................................................ 7

5 Classification ................................................................................................................. 8

5.1 General ................................................................................................................. 8

5.2 Principal magnetic properties ................................................................................ 8

5.3 Additional magnetic properties ............................................................................... 9

6 Chemical composition .................................................................................................. 10

7 Densities ..................................................................................................................... 10

8 Designation ................................................................................................................. 10

9 Mode of shipment and dimensions ............................................................................... 10

10 Testing ........................................................................................................................ 10

10.1 Extent of testing .................................................................................................. 10

10.2 Testing methods ................................................................................................. 10

11 Grounds for rejection ................................................................................................... 11

12 Description of tables of standard properties .................................................................. 11

12.1 Magnetically hard alloys ...................................................................................... 11

12.1.1 Aluminium-nickel-cobalt-iron-titanium alloys (AINiCo) ................................. 11

12.1.2 Chromium-iron-cobalt alloys (CrFeCo) .......................................................... 12

12.1.3 Iron-cobalt-vanadium-chromium alloys (FeCoVCr) ....................................... 12

12.1.4 Rare earth-cobalt alloys (RECo) .................................................................. 13

12.1.5 Rare earth-iron-boron alloys (REFeB) ........................................................... 14

12.2 Magnetically hard ceramics (magnetically hard ferrites) ...................................... 14

12.2.1 Chemical composition ................................................................................. 14

12.2.2 Manufacturing method ................................................................................. 15

12.2.3 Sub-classification ........................................................................................ 15

12.2.4 Magnetic properties and densities ................................................................ 15

12.2.5 Dimensional tolerances ................................................................................ 15

12.3 Bonded magnets ................................................................................................. 15

12.3.1 General ....................................................................................................... 15

12.3.2 Chemical composition .................................................................................. 15

12.3.3 Manufacturing method ................................................................................. 16

12.3.4 Sub-classification ........................................................................................ 16

12.3.5 Magnetic properties and densities ................................................................ 17

12.3.6 Dimensional tolerances ................................................................................ 17

13 Irreversible demagnetization behaviour ........................................................................ 17

13.1 General ............................................................................................................... 17

13.2 General definition of demagnetization field strength H ....................................... 18

13.3 Simplified definition of demagnetization field strength H ..................................... 18

14 Tables 10 to 23 ............................................................................................................ 20

Annex A (informative) Physical data and mechanical reference values of AINiCo,

CrFeCo, FeCoVCr, SmCo, NdFeB, hard ferrite and bonded SmFeN magnets ....................... 34

---------------------- Page: 4 ----------------------
IEC 60404-8-1:2015 © IEC 2015 – 3 –

Bibliography ....................................................................................................................... 36

Figure 1 – Graphic representation of B(H) and J(H) demagnetization and recoil curves ....... 19

Figure 2 – Simplified evaluation of B(H) and J(H) demagnetization and recoil curves ............ 20

Table 1 – Classification of magnetically hard materials .......................................................... 8

and units

Table 2 – Magnetic properties — Symbols .............................................................. 9

Table 3 – Additional magnetic properties — Symbols and units ............................................ 9

Table 4 — Chemical compositions of AlNiCo alloys (% mass fraction) ................................... 11

Table 5 — Chemical compositions of CrFeCo alloys (% mass fraction) ................................. 12

Table 6 — Chemical compositions of FeCoVCr alloys (% mass fraction) ............................... 12

Table 7 – Chemical compositions of RECo alloys (% mass fraction) ..................................... 13

Table 8 – Chemical compositions of REFeB alloys (% mass fraction) .................................. 14

Table 9 – Chemical compositions of REFeN alloys for bonded magnet (% mass

fraction) ............................................................................................................................. 16

Table 10 – Magnetic properties and densities of AlNiCo magnets ......................................... 21

Table 11 – Magnetic properties and densities of CrFeCo and FeCoVCr magnets .................. 22

Table 12 – Magnetic properties and densities of RECo magnets .......................................... 23

Table 13 – Magnetic properties and densities of REFeB magnets ........................................ 24

Table 14 – Magnetic properties and densities of hard ferrites ............................................... 25

Table 15 – Magnetic properties and densities of isotropic AlNiCo alloys with organic

binder ................................................................................................................................. 26

Table 16 – Magnetic properties and densities of RECo alloys with organic binder ................. 27

Table 17 – Magnetic properties and densities of isotropic REFeB alloys with organic

binder ................................................................................................................................. 28

Table 18 – Magnetic properties and densities of isotropic and anisotropic hard ferrites

with organic binder ............................................................................................................. 29

Table 19 – Magnetic properties and densities of anisotropic REFeN alloys with organic

binder ................................................................................................................................. 30

Table 20 – Dimensional tolerances (as cast or as sintered) of magnets made from

AlNiCo alloys ...................................................................................................................... 31

Table 21 – Dimensional tolerances of cold rolled strips of FeCoVCr and CrFeCo alloys

with a maximum thickness of 6 mm and maximum width of 125 mm ..................................... 32

Table 22 – Dimensional tolerances of the diameter of cold drawn wires and bars of

FeCoVCr and CrFeCo alloys ............................................................................................... 32

Table 23 – Dimensional tolerances on magnets made from hard ferrites .............................. 33

Table A.1 – Physical data and mechanical reference values of AlNiCo, CrFeCo,

FeCoVCr, SmCo, NdFeB, hard ferrite and bonded SmFeN magnets ..................................... 35

---------------------- Page: 5 ----------------------
– 4 – IEC 60404-8-1:2015 © IEC 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MAGNETIC MATERIALS –
Part 8-1: Specifications for individual materials –
Magnetically hard materials
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 60404-8-1 has been prepared by IEC technical committee 68:

Magnetic alloys and steels.
This third edition cancels and replaces the second edition published in 2001 and
Amendment 1:2004. This edition constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:
a) recently developed anisotropic Sm-Fe-N bonded magnets are included;
b) high energy ferrites with La and Co as substituents are included.
---------------------- Page: 6 ----------------------
IEC 60404-8-1:2015 © IEC 2015 – 5 –
The text of this standard is based on the following documents:
FDIS Report on voting
68/495/FDIS 68/503/RVD

Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

A list of all parts in the IEC 60404 series, published under the general title Magnetic materials,

can be found on the IEC website.

The committee has decided that the contents of this publication will remain unchanged until

the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data

related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
---------------------- Page: 7 ----------------------
– 6 – IEC 60404-8-1:2015 © IEC 2015
INTRODUCTION

This third edition of IEC 60404-8-1 includes the recently developed anisotropic Sm-Fe-N

bonded magnets and high energy ferrites with La and Co as substituents which have become

established in permanent magnet applications. It also includes corrections to the second

edition in order to improve consistency with IEC 60404-5. The squareness of the
demagnetization curve is introduced through the quantity H .
---------------------- Page: 8 ----------------------
IEC 60404-8-1:2015 © IEC 2015 – 7 –
MAGNETIC MATERIALS –
Part 8-1: Specifications for individual materials –
Magnetically hard materials
1 Scope

This part of IEC 60404 specifies minimum values for the principal magnetic properties of,

and dimensional tolerances for, technically important magnetically hard materials (permanent

magnets).

For information purposes only, this part of IEC 60404 provides values for the densities of

the materials and the ranges of their chemical compositions.

NOTE Some additional physical data and mechanical reference values concerning the magnetic materials are

given in Table A.1 for information and comparison purposes.
2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and

are indispensable for its application. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60050 (all parts), International Electrotechnical Vocabulary (available at:
www.electropedia.org)

IEC 60404-5, Magnetic materials – Part 5: Permanent magnet (magnetically hard) materials –

Methods of measurement of magnetic properties
3 Terms and definitions

For the purposes of this document, the terms and definitions given in IEC 60050-121 [1],

IEC 60050-151 [2] and IEC 60050-221 [3] apply.
4 Types of materials and their applications

Permanent magnetic materials, also designated as magnetically hard materials, are

classified in IEC 60404-1 [4] as Class R (magnetically hard alloys), Class S (magnetically

hard ceramics) and Class U (bonded magnets).

Permanent magnets have a coercivity relating to the magnetic polarization greater than

1 kA/m. After being magnetized to saturation they produce a material-dependent specific

magnetic energy, which can be used in static or dynamic magnetic circuit applications.

Permanent magnetic materials are used in nearly every area of daily life. They perform

coupling, modulating, or regulating functions in equipment and devices based on

electromagnetic principles, for example in measuring instruments, motors, generators and

_______________
Numbers in square brackets refer to the Bibliography.
---------------------- Page: 9 ----------------------
– 8 – IEC 60404-8-1:2015 © IEC 2015

loudspeakers. Permanent magnet materials are indispensable in office equipment and

computer hardware, automobiles including propulsion motors for Hybrid Electric Vehicles

(HEV) and Electric Vehicles (EV), entertainment electronics, telecommunications, household

appliances and medical instruments, as well as in mechanical engineering as holding

devices, clamping plates, etc.

Further possible and typical applications for the commercially available permanent magnetic

materials are described in more detail in 3.2 (Class R), 3.3 (Class S) and in 3.5

(Class U) of IEC 60404-1:2000.
5 Classification
5.1 General

Compared to IEC 60404-8-1:2001 and IEC 60404-8-1:2001/AMD1:2004, this revised edition

uses the same classification of permanent magnetic materials for technical applications. The

bonded REFeN magnets are newly added as U5 for the first part of the code number. This

is given in Table 1. The materials are grouped according to their metallurgical
classification
relationships.
Table 1 – Classification of magnetically hard materials
Group Principal constituents First part of code Previous code
number number
IEC 60404-8-1:2015 IEC 60404-8-
1:2001/AMD1:2004
Magnetically hard Aluminium-nickel-cobalt-iron-titanium R1 R1
alloys alloys
(R) Chromium-iron-cobalt alloys R6 R6
Iron-cobalt-vanadium-chromium alloys R3 R3
Rare earth-cobalt alloys R5 R5
Rare earth-iron-boron alloy R7 R7
Magnetically hard Magnetically hard ferrites S1 S1
ceramics
(MO･nFe O ; M = Ba, Sr, and/or Pb, and
2 3
(S)
n = 4,5 to 6,5)
Bonded hard Bonded aluminium-nickel-cobalt-iron- U1 U1
magnetic titanium magnets
materials
Bonded rare earth-cobalt magnets U2 U2
(U)
Bonded rare earth-iron-boron magnets U3 U3
Bonded hard ferrite magnets U4 U4
Bonded rare earth-iron-nitrogen magnets U5

The permanent magnetic materials are identified by the principal magnetic properties given

in 5.2.
5.2 Principal magnetic properties

Symbols and units of magnetic properties of magnetically hard materials are given in Table 2.

---------------------- Page: 10 ----------------------
IEC 60404-8-1:2015 © IEC 2015 – 9 –
and units
Table 2 – Magnetic properties — Symbols
Magnetic properties Symbol Unit
Maximum value of (BH) product (BH) kJ/m
max
Remanent flux density B mT
Coercivity relating to the magnetic flux density kA/m
Coercivity relating to the magnetic polarization H kA/m

Minimum values at room temperature of magnetic properties, determined after magnetization

to saturation, are given in Tables 10 to 19.

The specified values of magnetic properties are valid only for magnets having a cross

3 3

section invariable along the axis of magnetization, with a volume of 0,125 cm to 200 cm

and with dimensions in the three directions of the coordinate axes of at least 5 mm.

For anisotropic materials, they are valid only along the one preferred direction.

For more details on size limits for measurements, see IEC 60404-5.

For reasons connected with the manufacturing methods, lower values of the magnetic

properties may be obtained if the dimensional conditions mentioned above are not satisfied.

For the method of measurement of the coercivity of magnetic materials in an open magnetic

circuit, see IEC 60404-7 [5].
5.3 Additional magnetic properties

Symbols and units of additional magnetic properties of magnetically hard materials are given

in Table 3.
Table 3 – Additional magnetic properties — Symbols and un it s
Magnetic properties Symbol Unit
Recoil permeability µ —
rec
Temperature coefficient of the remanent flux
den s i ty [it corresponds to the temperature coefficient α(B ) %/°C
of the magnetic saturation α(J )]
Temperature coefficient of the coercivity relating to
α(H ) %/°C
the magnetic polarization
Curie temperature °C

The values given in Tables 10 to 19 are specified minimum values and some typical

values. The typical values are mean values published in the literature and are given as an

indication only and are not guaranteed. The temperature range for the temperature

coefficients in the tables is generally from 20 °C to 100 °C, but this does not preclude the

use of these materials outside this temperature range.

The magnetic field strength necessary for magnetizing magnetically hard materials to

magnetic saturation is defined in IEC 60404-5, IEC 60404-7 [5] and IEC TR 62517 [6].

---------------------- Page: 11 ----------------------
– 10 – IEC 60404-8-1:2015 © IEC 2015
6 Chemical composition

The composition ranges for the different material groups are given for information purposes

under 12.1.1.1, 12.1.2.1, 12.1.3.1, 12.1.4.1, 12.1.5.1, 12.2.1 and 12.3.2.
7 Densities

Density values are given in Tables 10 to 19 for information purposes only. The density

values can be used for mass and volume calculations.
8 Designation

Magnetically hard materials can be identified by brief designations and by alpha-numeric

symbols (code numbers, see Tables 10 to 19). In so far as chemical symbols are used in

the brief designation, they indicate main constituents. The number before the oblique stroke

in the brief designation denotes the maximum value of the (BH) product expressed in

kilojoules per cubic metre (kJ/m ) and the number after the oblique stroke denotes one tenth

of the coercivity H expressed in kiloamperes per metre (kA/m). Magnetically hard materials

with a binder (mostly organic, see 12.3.1) are denoted by a suffixed “p” to the brief

designation.

EXAMPLE For the grade AlNiCo 12/6 of Table 10, the integer 12 is obtained from its minimum value (BH) of

max

11,6 kJ/m , and the integer 6 from one-tenth of its minimum value of H i.e. one-tenth of 55 kA/m = 5,5 kA/m on

rounding up or down to the nearest integer. If rounding down would give the integer zero, the number containing

the first rounded non-zero decimal is maintained.
The code numbers are derived from the classification system used in IEC 60
...