IEC 60404-8-3:2023

Magnetic materials - Part 8-3: Specifications for individual materials - Cold-rolled non-oriented electrical steel strip and sheet delivered in the semi-processed state

IEC 60404-8-3:2023 defines the grades of cold-rolled non-oriented electrical steel strip and sheet delivered in the semi-processed state in nominal thicknesses of 0,47 mm, 0,50 mm, 0,64 mm, 0,65 mm and 0,79 mm. It gives general requirements, magnetic properties, geometric characteristics, tolerances and technical characteristics as well as inspection procedures. The nominal thicknesses of 0,47 mm, 0,64 mm and 0,79 mm apply to the grades for use at 60 Hz only.
This document applies to cold-rolled non-oriented electrical steel strip and sheet delivered in the semi-processed state, i.e. without final heat treatment, in coils or sheets, and intended for the construction of magnetic circuits. This document does not apply to materials supplied in the fully-processed state.
These materials correspond respectively to classes B2 and C21 of IEC 60404-1.
This edition includes the following significant technical changes with respect to the previous edition:
a) Modification of terms and technical requirements concerning geometrical characteristics to be consistent with IEC 60404-9:2018;
b) Insertion of Table 3 – Tolerances on nominal thickness;
c) Change of the length of the test specimen for determination of geometrical characteristics from 2 m to 1 m;
d) Deletion of Annex A with the European numerical system of designation of steels.

Matériaux magnétiques - Partie 8-3: Spécifications pour matériaux particuliers - Bandes et tôles magnétiques en acier à grains non orientés, laminées à froid et livrées à l'état semi fini

L’IEC 60404-8-3:2023 définit les grades des bandes et tôles magnétiques en acier à grains non orientés, laminées à froid et livrées à l'état semi fini d’épaisseurs nominales de 0,47 mm, 0,50 mm, 0,64 mm, 0,65 mm et 0,79 mm. Elle présente des exigences générales, des caractéristiques magnétiques, des caractéristiques géométriques, des tolérances et des caractéristiques techniques ainsi que des procédures de contrôle. Les épaisseurs nominales de 0,47 mm, 0,64 mm et 0,79 mm s'appliquent aux grades uniquement destinés à être utilisés à 60 Hz.
Le présent document s'applique aux bandes et tôles magnétiques en acier à grains non orientés, laminées à froid et livrées à l'état semi fini, à savoir n’ayant pas subi de traitement thermique final, en bobines ou en tôles, et destinées à la fabrication de circuits magnétiques. Le présent document ne s'applique pas aux matériaux livrés à l'état fini.
Ces matériaux magnétiques correspondent respectivement aux classes B2 et C21 de l’IEC 60404-1.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) Modification des termes et des exigences techniques relatifs aux caractéristiques géométriques à des fins de cohérence avec l’IEC 60404-9:2018;
b) Ajout du "Tableau 3 – Tolérances sur l’épaisseur nominale";
c) Modification de la longueur de l'éprouvette d’essai pour la détermination des caractéristiques géométriques de 2 m à 1 m;
d) Suppression de l'Annexe A relative au système européen de désignation numérique des aciers.

General Information

• Status: Published
• Publication Date: 26-Nov-2023
• ICS: 17.220.20 - Measurement of electrical and magnetic quantities
• ICS: 29.030 - Magnetic materials
• Technical Committee: TC 68 - Magnetic alloys and steels
• Drafting Committee: WG 1 - TC 68/WG 1
• Current Stage: PPUB - Publication issued
• Start Date: 27-Nov-2023
• Completion Date: 28-Dec-2023

Relations

• Revises: IEC 60404-8-3:2005 - Magnetic materials - Part 8-3: Specifications for individual materials - Cold-rolled electrical non-alloyed and alloyed steel sheet and strip delivered in the semi-processed state
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60404-8-3 ®
Edition 4.0 2023-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Magnetic materials –
Part 8-3: Specifications for individual materials – Cold-rolled non-oriented
electrical steel strip and sheet delivered in the semi-processed state

Matériaux magnétiques –
Partie 8-3: Spécifications pour matériaux particuliers – Bandes et tôles
magnétiques en acier à grains non orientés, laminées à froid et livrées à l'état
semi fini
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IEC 60404-8-3 ®
Edition 4.0 2023-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Magnetic materials –
Part 8-3: Specifications for individual materials – Cold-rolled non-oriented

electrical steel strip and sheet delivered in the semi-processed state

Matériaux magnétiques –
Partie 8-3: Spécifications pour matériaux particuliers – Bandes et tôles

magnétiques en acier à grains non orientés, laminées à froid et livrées à l'état

semi fini
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.20, 29.030 ISBN 978-2-8322-7912-0

– 2 – IEC 60404-8-3:2023 © IEC 2023
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Classification . 8
5 Designation . 8
6 General requirements . 9
6.1 Production process . 9
6.2 Form of supply . 9
6.3 Delivery condition . 9
6.4 Surface condition . 10
6.5 Suitability for cutting . 10
7 Technical requirements . 10
7.1 Magnetic properties . 10
7.1.1 Reference condition . 10
7.1.2 Magnetic polarization . 10
7.1.3 Specific total loss . 12
7.1.4 Anisotropy of loss . 13
7.2 Geometrical characteristics and tolerances . 13
7.2.1 Thickness . 13
7.2.2 Width . 14
7.2.3 Length . 14
7.2.4 Edge wave (wave factor) . 14
7.2.5 Edge camber . 15
7.3 Technological characteristics . 15
7.3.1 Density . 15
7.3.2 Stacking factor. 15
8 Inspection and testing . 15
8.1 General . 15
8.2 Selection of samples . 16
8.3 Preparation of test specimens . 16
8.3.1 Magnetic properties . 16
8.3.2 Geometrical characteristics and tolerances . 16
8.3.3 Stacking factor. 16
8.4 Test methods . 17
8.4.1 General . 17
8.4.2 Magnetic properties . 17
8.4.3 Geometrical characteristics and tolerances . 17
8.4.4 Stacking factor. 17
8.5 Retests . 17
9 Marking, labelling and packaging . 17
10 Complaints . 18
11 Information to be supplied by the purchaser . 18
Annex A (informative) Typical relative amplitude permeability . 19

Annex B (informative) Maximum specific total loss at 1,0 T . 20
Annex C (informative) Calculated density of non-oriented electrical steel . 21
Bibliography . 22

Table 1 – Technological and magnetic properties for use at 50 Hz (magnetic properties
are measured using the Epstein method according to IEC 60404-2) . 11
Table 2 – Technological and magnetic properties for use at 60 Hz (magnetic properties

are measured using the Epstein method according to IEC 60404-2) . 12
Table 3 – Tolerances on nominal thickness . 13
Table 4 – Tolerances on nominal width . 14
Table A.1 – Typical relative amplitude permeability values . 19
Table B.1 – Maximum specific total loss at 1,0 T . 20

– 4 – IEC 60404-8-3:2023 © IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MAGNETIC MATERIALS –
Part 8-3: Specifications for individual materials –
Cold-rolled non-oriented electrical steel strip and sheet
delivered in the semi-processed state

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
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
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shall not be held responsible for identifying any or all such patent rights.
IEC 60404-8-3 has been prepared by IEC technical committee 68: Magnetic alloys and steels.
It is an International Standard.
This fourth edition cancels and replaces the third edition published in 2005. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Modification of terms and technical requirements concerning geometrical characteristics to
be consistent with IEC 60404-9:2018;
b) Insertion of Table 3 – Tolerances on nominal thickness;

c) Change of the length of the test specimen for determination of geometrical characteristics
from 2 m to 1 m;
d) Deletion of Annex A with the European numerical system of designation of steels.
The text of this International Standard is based on the following documents:
Draft Report on voting
68/736/CDV 68/747/RVC
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
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 document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
– 6 – IEC 60404-8-3:2023 © IEC 2023
INTRODUCTION
TC 68 followed the recommendation of the maintenance inquiry, 68/649/INF, to revise this
standard in order to maintain consistency with other standard adaptions of the IEC 60404
series. Moreover, the revision is made mainly regarding testing and definitions of geometrical
characteristics in accordance with IEC 60404-9. The length of the test specimen for
determination of geometrical characteristics is changed from 2 m to 1 m. The term of "flatness"
is divided into "edge wave (wave factor)" and "residual curvature". This revision also includes
corrections in order to improve consistency with other IEC 60404-8 series. For example, the
supply in the form of coils is considered before the supply in sheets, which reflects the current
priority.
As the final annealing of cold-rolled non-oriented electrical steel strip and sheet delivered in the
semi-processed state is the responsibility of the user, attention is drawn to the importance of
this treatment for the properties of the product.
For this reason the magnetic properties in Table 1 and Table 2 are given for a reference
condition (see 7.1.1) obtained by a suitable heat treatment. To ensure that the properties in use
are equivalent to those specified, it is important that the heat treatment carried out by the user
is equivalent to that used to define the reference condition.
It is recognised that these products can be used in the semi-processed state, in which case the
magnetic properties are not subject to the specifications of this document.

MAGNETIC MATERIALS –
Part 8-3: Specifications for individual materials –
Cold-rolled non-oriented electrical steel strip and sheet
delivered in the semi-processed state

1 Scope
This part of IEC 60404 defines the grades of cold-rolled non-oriented electrical steel strip and
sheet delivered in the semi-processed state in nominal thicknesses of 0,47 mm, 0,50 mm,
0,64 mm, 0,65 mm and 0,79 mm. It gives general requirements, magnetic properties, geometric
characteristics, tolerances and technical characteristics as well as inspection procedures. The
nominal thicknesses of 0,47 mm, 0,64 mm and 0,79 mm apply to the grades for use at 60 Hz
only.
This document applies to cold-rolled non-oriented electrical steel strip and sheet delivered in
the semi-processed state, i.e. without final heat treatment, in coils or sheets, and intended for
the construction of magnetic circuits. This document does not apply to materials supplied in the
fully-processed state.
These materials correspond respectively to classes B2 and C21 of IEC 60404-1.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60050-121, International Electrotechnical Vocabulary (IEV) – Part 121: Electromagnetism
IEC 60050-221, International Electrotechnical Vocabulary (IEV) – Chapter 221: Magnetic
materials and components
IEC 60404-2, Magnetic materials – Part 2: Methods of measurement of the magnetic properties
of electrical steel sheet and strip by means of an Epstein frame
IEC 60404-9, Magnetic materials – Part 9: Methods of determination of the geometrical
characteristics of electrical steel strip and sheet
IEC 60404-13, Magnetic materials – Part 13: Methods of measurement of resistivity, density
and stacking factor of electrical steel strip and sheet
ISO 404, Steel and steel products – General technical delivery requirements
ISO 10474:1991, Steel and steel products – Inspection documents
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-121,
IEC 60050-221 and the following apply.

– 8 – IEC 60404-8-3:2023 © IEC 2023
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
edge wave
wave factor
variations of flatness of a length of strip or a sheet taking a form of waves at the slit edge of the
product
Note 1 to entry: The edge wave is characterized by the wave factor which is the relation of the height of the wave
to its length, expressed as a percentage.
[SOURCE IEC 60404-9:2018, 3.1]
3.2
residual curvature
variations of flatness of a length of strip or a sheet taking a permanent curvature in the direction
of rolling of the product
[SOURCE IEC 60404-9:2018, 3.2]
3.3
edge camber
greatest distance between a longitudinal edge of a length of strip or sheet and the line joining
the two extremities of the measured length of this edge
[SOURCE IEC 60404-9:2018, 3.3]
4 Classification
The grades covered by this document are classified according to the specified value of the
maximum specific total loss in watts per kilogram after a reference heat treatment (see 7.1.1)
and according to the nominal thickness of the product . Products of the nominal thickness
0,50 mm and 0,65 mm are classified according to the specified value of maximum specific total
loss, tested at a magnetic polarization of 1,5 T and 50 Hz, in watts per kilogram. The products
of the nominal thickness of 0,47 mm, 0,64 mm and 0,79 mm are classified according to the
specified value of the maximum specific total loss, tested at a magnetic polarization of 1,5 T
and 60 Hz, in watts per kilogram.
5 Designation
The steel name comprises the following in the order given:
a) a letter "M" for electrical steel;
b) one hundred times the specified value of maximum specific total loss at a magnetic
polarization of 1,5 T and 50 Hz, in watts per kilogram, for the products of the nominal
thicknesses 0,50 mm and 0,65 mm, or at a magnetic polarization of 1,5 T and 60 Hz, in
watts per kilogram, for the products of the nominal thicknesses 0,47 mm, 0,64 mm and
0,79 mm;
c) one hundred times the nominal thickness of the product, in millimetres;
___________
In the rest of the document, the word "product" is used to mean "strip and sheet".

d) the characteristic letter "K" for the grades of cold-rolled non-oriented electrical steel strip or
sheet delivered in the semi-processed state;
e) one tenth of the frequency at which the maximum specific total loss is specified, i.e. 5 or 6.
EXAMPLE: M660-50K5 for cold-rolled electrical steel strip or sheet with a specified maximum specific total loss of
6,60 W/kg at a magnetic polarization of 1,5 T at 50 Hz and a nominal thickness of 0,50 mm, supplied in the semi-
processed state.
6 General requirements
6.1 Production process
The production process of the steel and its chemical composition are left to the discretion of
the manufacturer.
6.2 Form of supply
The product is supplied in coils in the case of strip and bundles in the case of sheets.
The mass of coils or bundles of sheets shall be agreed between the manufacturer and purchaser
at the time of enquiry and order.
The recommended value for internal diameter of coils is approximately 508 mm or
approximately 610 mm.
Strip shall be of constant width and wound in such a manner that the edges are superimposed
in a regular manner and the side faces of the coil are substantially flat.
Coils shall be sufficiently tightly wound in order that they do not collapse under their own weight.
Strip can exhibit welds or interleaves resulting from the removal of defective zones, if agreed
between the manufacturer and the purchaser at the time of enquiry and order. If necessary, the
marking of welds or interleaves can be agreed between the manufacturer and the purchaser at
the time of enquiry and order.
For coils containing welds or interleaves, each part of the strip shall be of the same grade.
The edges of parts welded together shall not be so much out of alignment as to affect the further
processing of the product.
Sheets which make up each bundle shall be stacked so that the side faces of the stack are
substantially flat and approximately perpendicular to the top face.
6.3 Delivery condition
The products supplied with slit or trimmed edges shall not have any burrs which will adversely
affect its further application or use.
As the result of the method of manufacture and delivery in the form of coils, the products in the
as-delivered condition can exhibit residual curvature in the direction of rolling as well as certain
internal stresses. Precautions shall be taken by the user to reduce or eliminate the effect of
these factors on the application or use of the products.
The products can be supplied either without insulating coating or with thin insulating coating on
one or both sides which can act as an "anti-stick" coating during anneal.
NOTE For the classification of surface insulation coatings, see IEC 60404-1-1.

– 10 – IEC 60404-8-3:2023 © IEC 2023
6.4 Surface condition
The surfaces shall be smooth and clean. Dispersed defects such as scratches, blisters, cracks,
etc. are only permitted if they are within the tolerances on thickness and if they are not
detrimental to the correct use of the supplied product.
The surface condition and in particular the roughness of the products can be the subject of
agreement between the manufacturer and the purchaser at the time of enquiry and order.
6.5 Suitability for cutting
The product shall be able to be cut or punched without causing premature wear of tools. The
product shall be suitable for cutting or punching accurately into the usual shapes at any point
when appropriate cutting or punching tools and technologies are used.
A special requirement concerning suitability for cutting or punching of the product can be subject
to agreement between the manufacturer and the purchaser at the time of enquiry and order.
7 Technical requirements
7.1 Magnetic properties
7.1.1 Reference condition
The properties defined in 7.1.2 to 7.1.4 shall only apply to test specimens in the reference
condition which is obtained by the following heat treatment.
Test strips shall be subjected to a heat treatment in a decarburizing atmosphere at the
temperature specified in Table 1 or Table 2 and shall be maintained for 2 h at this temperature.
The heating rate shall not exceed 200 °C/h. The cooling rate from the temperatures specified
in Table 1 or Table 2 to 550 °C shall not exceed 120 °C/h. The gas for decarburization
atmosphere shall have a volume fraction of 20 % H , 80 % N with water vapour, the dew-point
2 2
being +13 °C ± 2 °C to +20 °C ± 2 °C at atmospheric pressure.
NOTE In special cases, the manufacturer can recommend a non-standard reference treatment, for example in a
non-decarburizing atmosphere for material with a very low carbon content.
The establishment of the decarburizing atmosphere requires the removal of air from the
annealing furnace before raising the temperature. This removal is effected by continuously
purging the furnace with an inert protective gas. The flow and pressure of the decarburizing gas
shall be regulated to ensure good decarburization at any point on the test specimen and a
complete renewal of the atmosphere in the furnace several times during the heat treatment.
The test strips should not have any contact with each other.
7.1.2 Magnetic polarization
The specified values of minimum magnetic polarization, expressed as a peak value, at AC
magnetic field strength values H of 2 500 A/m, 5 000 A/m and 10 000 A/m, expressed as a peak
value, shall be given in Table 1 at 50 Hz and Table 2 at 60 Hz.
NOTE Annex A gives, for guidance only, typical values of relative amplitude permeability for steels of nominal
thicknesses 0,47 mm, 0,64 mm and 0,79 mm.

Table 1 – Technological and magnetic properties for use at 50 Hz (magnetic properties
are measured using the Epstein method according to IEC 60404-2)
Steel name Nominal Reference Maximum specific Minimum magnetic polarization at Conven-
a, b
thickness heat total loss at tional
an AC magnetic field strength
a c
treatment
1,5 T density
temperature
mm °C W/kg T
kg/dm
d
(±10 °C) 50 Hz 60 Hz 2 500 A/m 5 000 A/m 10 000 A/m
M340-50K5 840 3,40 4,32 1,54 1,62 1,72 7,65
M390-50K5 840 3,90 4,97 1,56 1,64 1,74 7,70
M450-50K5 790 4,50 5,67 1,57 1,65 1,75 7,75
M560-50K5 0,50 790 5,60 7,03 1,58 1,66 1,76 7,80
M660-50K5 790 6,60 8,38 1,62 1,70 1,79 7,85
M890-50K5 790 8,90 11,30 1,60 1,68 1,78 7,85
M1050-50K5 790 10,50 13,34 1,57 1,65 1,77 7,85
M390-65K5 840 3,90 5,07 1,54 1,62 1,72 7,65
M450-65K5 840 4,50 5,86 1,56 1,64 1,74 7,70
M520-65K5 790 5,20 6,72 1,57 1,65 1,75 7,75
M630-65K5 0,65 790 6,30 8,09 1,58 1,66 1,76 7,80
M800-65K5 790 8,00 10,16 1,62 1,70 1,79 7,85
M1000-65K5 790 10,00 12,70 1,60 1,68 1,78 7,85
M1200-65K5 790 12,00 15,24 1,57 1,65 1,77 7,85
a
These values are valid only for test specimens in the reference condition (see 7.1.1).
b
It has been common practice for many years to give values of magnetic flux density. In fact the Epstein frame
is used to determine magnetic polarization (intrinsic flux density) which is defined as follows in accordance
with IEC 60050-121:
J = B – µ H
where
J is the magnetic polarization;
B is the magnetic flux density;
-7 -1
µ is the magnetic constant: 4 π × 10 Hm ;
H is the magnetic field strength.
NOTE The difference between B and J at 10 000 A/m is equal to 0,013 T.
c
Other values can be agreed between the steel manufacturer and the purchaser at the time of enquiry and
order, see Annex C.
d
Only for information.
– 12 – IEC 60404-8-3:2023 © IEC 2023
Table 2 – Technological and magnetic properties for use at 60 Hz (magnetic properties
are measured using the Epstein method according to IEC 60404-2)
Steel name Nominal Reference heat Maximum specific Minimum magnetic polarization at Conven-
a a, b
thickness treatment tional
total loss at 1,5 T an AC magnetic field strength
c
temperature
density
mm °C W/kg T
kg/dm
d
(±10 °C) 60 Hz 50 Hz 2 500 A/m 5 000 A/m 10 000 A/m
M342-47K6 840 3,42 2,70 1,52 1,60 1,70 7,65
M364-47K6 840 3,64 2,88 1,53 1,60 1,70 7,65
M386-47K6 840 3,86 3,05 1,53 1,61 1,71 7,65
M419-47K6 840 4,19 3,31 1,54 1,62 1,72 7,70
M441-47K6 0,47 790 4,41 3,48 1,54 1,62 1,72 7,70
M507-47K6 790 5,07 4,01 1,57 1,65 1,75 7,75
M595-47K6 790 5,95 4,70 1,58 1,66 1,76 7,80
M728-47K6 790 7,28 5,75 1,59 1,67 1,77 7,80
M838-47K6 790 8,38 6,62 1,60 1,68 1,78 7,85
M441-64K6 840 4,41 3,48 1,52 1,60 1,70 7,65
M463-64K6 840 4,63 3,66 1,52 1,60 1,70 7,65
M485-64K6 840 4,85 3,83 1,53 1,61 1,71 7,65
M507-64K6 840 5,07 4,01 1,54 1,62 1,72 7,70
M573-64K6 0,64 790 5,73 4,53 1,56 1,64 1,74 7,70
M640-64K6 790 6,40 5,06 1,57 1,65 1,75 7,75
M794-64K6 790 7,94 6,27 1,58 1,66 1,76 7,80
M948-64K6 790 9,48 7,49 1,60 1,68 1,78 7,80
M1080-64K6 790 10,80 8,53 1,60 1,68 1,78 7,85
M992-79K6 790 9,92 7,84 1,57 1,65 1,75 7,75
M1190-79K6 0,79 790 11,90 9,42 1,58 1,66 1,76 7,80
M1350-79K6 790 13,50 10,67 1,59 1,67 1,77 7,85
a
These values are valid only for test specimens in the reference condition (see 7.1.1).
b
It has been common practice for many years to give values of magnetic flux density. In fact the Epstein frame
is used to determine magnetic polarization (intrinsic flux density) which is defined as follows in accordance
with IEC 60050-121:
J = B – µ H
where
J is the magnetic polarization;
B is the magnetic flux density;
-7 -1
µ is the magnetic constant: 4 π × 10 Hm ;
H is the magnetic field strength.
NOTE The difference between B and J at 10 000 A/m is equal to 0,013 T.
c
Other values can be agreed between the steel manufacturer and the purchaser at the time of enquiry and
order, see Annex C.
d
Only for information.
7.1.3 Specific total loss
The specified values of maximum specific total loss at a magnetic polarization of 1,5 T and
50 Hz shall be as given in Table 1 for products of the nominal thicknesses 0,50 mm and
0,65 mm.
The specified values of maximum specific total loss at a magnetic polarization of 1,5 T and
60 Hz shall be as given in Table 2 for products of the nominal thicknesses of 0,47 mm, 0,64 mm
and 0,79 mm.
The test shall be made in an alternating magnetic field at 50 Hz for the materials given in Table 1
or at 60 Hz for the materials given in Table 2.
NOTE Annex B gives, for guidance only, the maximum specific total loss for a magnetic polarization of 1,0 T at
50 Hz and for nominal thicknesses 0,50 mm and 0,65 mm.
7.1.4 Anisotropy of loss
A special requirement concerning the anisotropy of loss can be subject to agreement between
the manufacturer and the purchaser at the time of enquiry and order.
7.2 Geometrical characteristics and tolerances
7.2.1 Thickness
The nominal thicknesses of the product are 0,47 mm, 0,50 mm, 0,64 mm, 0,65 mm and
0,79 mm.
The nominal thicknesses 0,50 mm and 0,65 mm apply to the grades for use at 50 Hz.
The nominal thicknesses 0,47 mm, 0,64 mm and 0,79 mm apply to the grades for use at 60 Hz.
For thickness tolerance, a distinction is made between
– the deviation from the nominal thickness within the same acceptance unit,
– the difference in thickness in a direction parallel to the direction of rolling in a length of strip
or sheet,
– the difference in thickness in a direction perpendicular to the direction of rolling. This
tolerance applies only to products supplied with a width greater than 150 mm.
At any point, the deviation from the nominal thickness within the same acceptance unit shall
not exceed the tolerance of Table 3.
Table 3 – Tolerances on nominal thickness
Nominal thickness Tolerance
mm mm
0,47 ±0,038
0,50 ±0,040
0,64 ±0,051
0,65 ±0,052
0,79 ±0,063
The additional thickness due to welds, with respect to the measured thickness of the product
shall not exceed 0,10 mm.
The difference in thickness in a direction parallel to the direction of rolling in a 1 m length of the
product shall not exceed 0,038 mm, 0,040 mm, 0,051 mm, 0,052 mm and 0,063 mm for
products of the nominal thickness 0,47 mm, 0,50 mm, 0,64 mm, 0,65 mm and 0,79 mm
respectively.
– 14 – IEC 60404-8-3:2023 © IEC 2023
For products with a width greater than 150 mm, the difference in thickness in a direction
perpendicular to the direction of rolling shall not exceed
– 0,020 mm for products of the nominal thicknesses 0,47 mm and 0,50 mm;
– 0,030 mm for products of the nominal thicknesses 0,64 mm and 0,65 mm;
– 0,040 mm for products of the nominal thickness 0,79 mm.
The measurements shall be made at any point located at least 20 mm from the edges (see
8.4.3.1). For narrow strips, other agreements can be necessary.
7.2.2 Width
The commonly available nominal widths are less than or equal to 1 250 mm.
For the tolerances on width, a distinction is made between products supplied with slit or trimmed
edges and products supplied with as-rolled edges.
For products supplied with slit or trimmed edges, the tolerances of Table 4 shall apply.
Table 4 – Tolerances on nominal width
a
Nominal width, l Tolerance
mm mm
+0,2
l ≤ 150
+0,3
150 < l ≤ 300
+0,5
300 < l ≤ 600
+1,0
600 < l ≤ 1 000
+1,5
b
1 000 < l ≤ 1 250
a
By agreement between the manufacturer and the purchaser at the time of enquiry
and order, the tolerances on the nominal width may be all minus tolerances.
b
Nominal widths greater than 1 250 mm may be delivered. In this case the tolerance
should be agreed between the manufacturer and purchaser at the time of enquiry
and order.
+5
For products supplied with as-rolled edges, the tolerances on nominal width shall be mm.
7.2.3 Length
The verification of length does not apply to products supplied in coils.
For products supplied in sheets, the tolerance on the length of sheets in relation to the length
+0,5
ordered shall be %, but with a maximum of +6 mm.
7.2.4 Edge wave (wave factor)
The verification of edge wave applies only to products supplied with a width greater than
100 mm. The edge wave (wave factor) is specified only for products supplied with slit or trimmed
edges. The wave factor (see 8.4.3.3), shall not exceed 2 %.

7.2.5 Edge camber
The verification of edge camber applies only to products supplied with a width greater than
30 mm. A distinction is made between products supplied with as-rolled edges and products
supplied with slit or trimmed edges.
For products supplied with as-rolled edges, the edge camber shall not exceed 6 mm for a
measuring length of 1 m.
For products supplied with slit or trimmed edges, the edge camber shall not exceed 4 mm for a
measuring length of 1 m.
7.3 Technological characteristics
7.3.1 Density
The density of the products is not specified.
The conventional values of density, used to calculate the magnetic properties and stacking
factor, shall be as given in Table 1 and Table 2. Other values can be agreed between the
manufacturer and the purchaser at the time of enquiry and order (see Table 1 and Table 2,
footnote c).
7.3.2 Stacking factor
The stacking factor can be subject to an agreement between the manufacturer and the
purchaser at the time of enquiry and order.
8 Inspection and testing
8.1 General
The products defined by this document can be ordered with or without specific inspection in
accordance with ISO 404. However, as a dispensation from ISO 404, in the case of an order
without inspection, the manufacturer shall supply an inspection document type 3.1 according to
ISO 10474 giving the specific total loss of the supplied product in the reference condition (see
7.1.1).
In the case of an order with specific inspection, the type of inspection document in accordance
with ISO 10474 shall be specified when ordering. In this case, the delivery is divided into
acceptance units.
Each acceptance unit shall comprise 20 t or the remaining fraction thereof of the same grade
and the same nominal thickness. Different acceptance units can be adopted by special
agreement between the manufacturer and the purchaser at the time of enquiry and order.
For coils of more than 20 t, each coil shall constitute an acceptance unit.
When the products are delivered in the form of slit coils, the test results applying to the parent
coil of the acceptance unit shall apply.

– 16 – IEC 60404-8-3:2023 © IEC 2023
8.2 Selection of samples
Test samples shall be taken from each acceptance unit.
In the case of coils, the first internal turn and the last external turn of the coil shall be considered
as wrapping and not representative of the quality of the rest of the coil. The selection shall be
made from the first external and/or internal turn, excluding the wrapping turn and outside any
welding zones or interleaves. Should the sample be taken from the internal bore, sample
deformation can be present that can affect the magnetic property results.
In the case of sheets, the selection shall preferably be made from the upper part of the bundle.
By choosing a suitable order for the execution of tests, the same sample shall serve to verify
the various properties.
8.3 Preparation of test specimens
8.3.1 Magnetic properties
For the measurement of magnetic polarization and specific total loss, using the 25 cm Epstein
frame in accordance with IEC 60404-2, the test specimen shall consist of a minimum of 16
Epstein test strips for nominal product thicknesses <0,64 mm and a minimum of 12 Epstein
strips for nominal product thicknesses ≥0,64 mm. The dimensions of the test strips shall be as
follows:
– length 280 mm to 310 mm, the lengths being equal within a tolerance of ±0,5 mm;
– width 30 mm within a tolerance of ±0,2 mm.
Half the test strips shall be cut parallel to the direction of rolling and the other half of the test
strips shall be cut perpendicular to the direction of rolling. The permitted tolerance for the angle
between the specified direction and the direction of cutting or punching is ±5°.
As far as possible, the selection of test strips shall be made uniformly across the width of the
product. The test strips shall be carefully cut without deformation. The cutting or punching shall
be carried out with well sharpened tools.
If the width of the product is insufficient for a sample of test strips to be taken perpendicular to
the direction of rolling, the test strips shall be taken in the direction of rolling only.
8.3.2 Geometrical characteristics and tolerances
For the measurement of thickness, width, edge wave (wave factor) and edge camber, the test
specimen shall consist of a 1 m length of strip or sheet.
8.3.3 Stacking factor
The test specimen shall consist of at least 16 strips of the same size for nominal product
thicknesses < 0,64 mm and a minimu
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