IEC 60404-8-7:2020

IEC 60404-8-7 ®
Edition 5.0 2020-09
INTERNATIONAL
STANDARD
Magnetic materials –
Part 8-7: Specifications for individual materials – Cold-rolled grain-oriented
electrical steel strip and sheet delivered in the fully-processed state
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IEC 60404-8-7 ®
Edition 5.0 2020-09
INTERNATIONAL
STANDARD
Magnetic materials –
Part 8-7: Specifications for individual materials – Cold-rolled grain-oriented

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

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.030 ISBN 978-2-8322-8779-8

– 2 – IEC 60404-8-7:2020  IEC 2020
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Classification . 8
5 Designation . 9
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 General . 10
7.1.2 Magnetic polarization . 10
7.1.3 Specific total loss . 10
7.1.4 Magnetic properties of magnetic domain refined high permeability
grades . 10
7.2 Geometric 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 Residual curvature . 15
7.2.6 Edge camber . 15
7.2.7 Burr height . 15
7.3 Technological characteristics . 15
7.3.1 Density . 15
7.3.2 Stacking factor. 15
7.3.3 Number of bends . 15
7.3.4 Deviation from the shearing line (internal stress) . 15
7.3.5 Insulation coating resistance . 15
8 Inspection and testing . 16
8.1 General . 16
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 . 17
8.3.3 Technological characteristics . 17
8.4 Test methods . 18
8.4.1 General . 18
8.4.2 Magnetic properties . 18
8.4.3 Geometrical characteristics and tolerances . 18

8.4.4 Technological characteristics . 18
8.5 Retests . 19
9 Marking, labelling and packaging . 19
10 Complaints . 19
11 Information to be supplied by the purchaser . 19
Bibliography . 21

Table 1 – Technological and magnetic properties of the conventional grades of grain-
oriented electrical steel strip and sheet (magnetic properties are measured using the
Epstein method according to IEC 60404-2) . 11
Table 2 – Technological and magnetic properties of the high permeability grades of
grain-oriented electrical steel strip and sheet (magnetic properties are measured using
the Epstein method according to IEC 60404-2) . 12
Table 3 – Technological and magnetic properties of magnetic domain refined high
permeability grades of grain-oriented electrical steel strip and sheet (magnetic
properties are measured using the Single Sheet Test method* according
to IEC 60404-3). . 13
Table 4 – Tolerances on nominal thickness . 14
Table 5 – Tolerances on nominal width . 14

– 4 – IEC 60404-8-7:2020  IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MAGNETIC MATERIALS –
Part 8-7: Specifications for individual materials –
Cold-rolled grain-oriented electrical steel strip and sheet
delivered in the fully-processed state

FOREWORD
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International Standard IEC 60404-8-7 has been prepared by IEC technical committee 68:
Magnetic alloys and steels.
This fifth edition cancels and replaces the fourth edition published in 2017. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– insertio
...