IEC 60404-8-5:2020

Magnetic materials - Part 8-5: Specifications for individual materials - Electrical steel strip and sheet with specified mechanical properties and magnetic polarization

IEC 60404-8-5:2020(E) defines the grades of electrical steel strip and sheet with specified mechanical properties and magnetic polarization. In particular, it gives general requirements, mechanical properties, magnetic polarization, geometric characteristics, tolerances and technological characteristics, as well as inspection procedures.
This document applies to electrical steel strip and sheet intended for the construction of poles and rims of rotating electrical machines.
The grades are grouped into two classes according to their manufacturing process:
- hot-rolled grades;
- cold-rolled grades.
They correspond to Class D21 of IEC 60404-1.
This edition includes the following significant technical changes with respect to the previous edition:
a) extension of the range of products to include the improved grades;
b) division of "flatness" into "edge wave (wave factor)" and "residual curvature" in consistent with IEC 60404-9;
c) change length of test specimen for determinations of geometrical characters from 2 m to 1 m.

General Information

• Status: Published
• Publication Date: 17-Aug-2020
• 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
• Drafting Committee: WG 1 - TC 68/WG 1
• Current Stage: PPUB - Publication issued
• Start Date: 18-Aug-2020
• Completion Date: 09-Sep-2020

Overview

IEC 60404-8-5:2020 - Magnetic materials - Part 8-5: Specifications for individual materials - Electrical steel strip and sheet with specified mechanical properties and magnetic polarization - defines standardized grades and requirements for electrical steel strip and sheet used primarily in the poles and rims of rotating electrical machines. The standard sets out mechanical properties, magnetic polarization, geometrical characteristics, tolerances, technological characteristics and inspection procedures for both hot‑rolled and cold‑rolled grades (Class D21 of IEC 60404‑1).

Key technical updates in the 2020 edition:

• Inclusion of improved grades.
• Splitting of flatness into edge wave (wave factor) and residual curvature, aligning with IEC 60404‑9.
• Reduction of the test specimen length for geometrical determinations from 2 m to 1 m.

Key Topics and Requirements

• Classification and designation of hot‑rolled and cold‑rolled electrical steel strip and sheet.
• General requirements covering production process, form of supply, delivery condition and surface state.
• Mechanical properties: specified proof strength and tensile characteristics (as applicable to design and manufacturability).
• Magnetic polarization: defined magnetic performance parameters and test methods.
• Geometrical characteristics and tolerances: thickness, width, length, edge wave (wave factor), residual curvature, edge camber and related tolerance tables.
• Technological characteristics: e.g., density and suitability for cutting and welding.
• Inspection and testing: sampling, specimen preparation, test methods (references include Epstein frame methods in IEC 60404‑2 and d.c. measurements in IEC 60404‑4), retest rules and documentation.
• Marking, labelling, packaging and purchaser information requirements.

Applications and Who Uses This Standard

IEC 60404‑8‑5 is essential for:

• Steel manufacturers and mills producing electrical steel strip and sheet.
• Designers and manufacturers of rotating electrical machines (motors, generators) specifying pole and rim materials.
• Quality assurance and inspection teams ensuring conformity to magnetic and mechanical specifications.
• Procurement and technical purchasers who require clear material specifications and tolerances.
• Test laboratories using standardized methods (Epstein frame, d.c. tests) to verify magnetic polarization.

Practical benefits:

• Ensures consistent magnetic performance and mechanical strength for machine reliability.
• Reduces manufacturing issues by defining cut/weld suitability and flatness tolerances.
• Streamlines procurement with standardized grade designations and inspection procedures.

Related Standards

• IEC 60404‑1 (Classification)
• IEC 60404‑2 (Epstein frame measurement methods)
• IEC 60404‑4 (d.c. magnetic property measurement)
• IEC 60404‑9 (Geometrical characteristics methods)
• ISO 404, ISO 2566‑1, ISO 6892‑1 (related steel product and test method standards)

Keywords: IEC 60404-8-5, electrical steel strip and sheet, magnetic materials, magnetic polarization, mechanical properties, tolerances, rotating electrical machines, edge wave, residual curvature.

Standards Content (Sample)

IEC 60404-8-5 ®
Edition 2.0 2020-08
INTERNATIONAL
STANDARD
Magnetic materials –
Part 8-5: Specifications for individual materials – Electrical steel strip and sheet
with specified mechanical properties and magnetic polarization
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IEC 60404-8-5 ®
Edition 2.0 2020-08
INTERNATIONAL
STANDARD
Magnetic materials –
Part 8-5: Specifications for individual materials – Electrical steel strip and sheet

with specified mechanical properties and magnetic polarization

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.030; 17.220.20 ISBN 978-2-8322-8747-7

– 2 – IEC 60404-8-5:2020 © IEC 2020
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Classification . 8
5 Designation . 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
6.6 Suitability for welding . 10
7 Technical requirements . 10
7.1 Mechanical properties . 10
7.2 Magnetic polarization . 10
7.3 Geometrical characteristics and tolerances . 12
7.3.1 Thickness . 12
7.3.2 Width . 14
7.3.3 Length . 14
7.3.4 Edge wave (wave factor) . 15
7.3.5 Residual curvature . 15
7.3.6 Edge camber . 16
7.4 Technological characteristics . 16
7.4.1 Density . 16
8 Inspection and testing . 16
8.1 General . 16
8.2 Selection of test samples . 17
8.3 Preparation of test specimens . 17
8.3.1 Mechanical properties . 17
8.3.2 Magnetic polarization . 17
8.3.3 Geometrical characteristics and tolerances . 18
8.4 Test methods . 18
8.4.1 General . 18
8.4.2 Mechanical properties . 18
8.4.3 Magnetic polarization . 18
8.4.4 Geometrical characteristics and tolerances . 18
8.5 Retests . 19
9 Marking, labelling and packaging . 19
10 Complaints . 19
11 Information to be supplied by the purchaser . 19

Table 1 – Mechanical and magnetic characteristics for hot-rolled grades . 11
Table 2 – Mechanical and magnetic characteristics for cold-rolled grades . 12

Table 3 – Tolerance on nominal thickness for hot-rolled grades . 13
Table 4 – Tolerance on nominal thickness for cold-rolled grades . 13
Table 5 – Maximum difference in thickness in a direction perpendicular to the direction
of rolling for hot-rolled grades . 13
Table 6 – Maximum difference in thickness in a direction perpendicular to the direction
of rolling for cold-rolled grades . 14
Table 7 – Tolerance on nominal width of products supplied with trimmed edges . 14
Table 8 – Tolerance on nominal length of sheets . 15
Table 9 – Maximum distance between the lower face of a test specimen and the flat
surface table for hot-rolled grades . 15
Table 10 – Maximum distance between the lower face of a test specimen and the flat
surface table for cold-rolled grades . 16
Table 11 – Minimum number of Epstein test strips . 17

– 4 – IEC 60404-8-5:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MAGNETIC MATERIALS –
Part 8-5: Specifications for individual materials –
Electrical steel strip and sheet with specified mechanical
properties and magnetic polarization

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
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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 60404-8-5 has been prepared by IEC technical committee 68:
Magnetic alloys and steels.
This second edition cancels and replaces the first edition published in 1989. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) extension of the range of products to include the improved grades;
b) division of "flatness" into "edge wave (wave factor)" and "residual curvature" in consistent
with IEC 60404-9;
c) change length of test specimen for determinations of geometrical characters from 2 m to
1 m.
The text of this International Standard is based on the following documents:
CDV Report on voting
68/648/CDV 68/662/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.
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 "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.
– 6 – IEC 60404-8-5:2020 © IEC 2020
INTRODUCTION
The first edition of IEC 60404-8-5, "Magnetic materials – Part 8: Specifications for individual
materials – Section Five – Specification for steel sheet and strip with specified mechanical
properties and magnetic permeability", was published in April 1989 and has not been revised
for more than 30 years. Since then, new grades of cold-rolled material of minimum proof
strength R greater than 400 MPa were developed and widely used. Thus, IEC TC 68
p0,2
decided in 2017 at their meeting in Paris to revise this document. This revision also includes
corrections to the first edition in order to improve consistency with the other parts of the
IEC 60404-8 subseries.
MAGNETIC MATERIALS –
Part 8-5: Specifications for individual materials –
Electrical steel strip and sheet with specified mechanical
properties and magnetic polarization

1 Scope
This part of IEC 60404 defines the grades of electrical steel strip and sheet with specified
mechanical properties and magnetic polarization. In particular, it gives general requirements,
mechanical properties, magnetic polarization, geometric characteristics, tolerances and
technological characteristics, as well as inspection procedures.
This document applies to electrical steel strip and sheet intended for the construction of poles
and rims of rotating electrical machines.
The grades are grouped into two classes according to their manufacturing process:
– hot-rolled grades;
– cold-rolled grades.
They correspond to Class D21 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 – Part 121: Electromagnetism
IEC 60050-221, International Electrotechnical Vocabulary – Chapter 221: Magnetic materials
and components
IEC 60404-1, Magnetic materials – Part 1: Classification
IEC 60404-2, Magnetic materials – Part 2: Methods of measurement of the magnetic
properties of electrical steel strip and sheet by means of an Epstein frame
IEC 60404-4, Magnetic materials – Part 4: Methods of measurement of d.c. magnetic
properties of iron and steel
IEC 60404-9, Magnetic materials – Part 9: Methods of determination of the geometrical
characteristics of electrical steel strip and sheet
ISO 404, Steel and steel products – General technical delivery requirements
ISO 2566-1, Steel – Conversion of elongation values – Part 1: Carbon and low alloy steels
ISO 6892-1, Metallic materials – Tensile testing – Part 1: Method of test at room temperature

– 8 – IEC 60404-8-5:2020 © IEC 2020
ISO 10474, 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, IEC 60404-9 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://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: 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 rolling
direction 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 a 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
minimum proof strength R , in MPa , according to the specified value of minimum magnetic
p0,2
polarization at a DC magnetic field strength of 15 000 A/m, in T, and according to the nominal
thickness of the product , in mm.
5 Designation
The steel name comprises the following in the order given:
a) the characteristic letters
– "TG" for hot-rolled grades;
– "TF" for cold-rolled grades;
___________
1 MPa =1 N/mm .
In the rest of the document, the word "product" is used to mean "strip and sheet".

b) the specified value of minimum proof strength Rp0,2, in MPa;
c) one hundred times the nominal thickness of the product, in mm;
d) one hundred times the specified value of minimum magnetic polarization at a DC magnetic
field strength of 15 000 A/m, in T.
EXAMPLE: TF350-100-181 for cold-rolled electrical steel strip and sheet with a minimum proof strength R of
p0,2
350 MPa, a nominal thickness of 1,0 mm, and a minimum magnetic polarization of 1,81 T at a DC magnetic field
strength of 15 000 A/m.
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 in bundles in the case of sheets.
The mass of the coils or bundles of sheets shall be agreed between the manufacturer and the
purchaser at the time of enquiry and order.
The internal diameter of coils shall be agreed between the manufacturer and the purchaser at
the time of enquiry and order. The recommended value for the internal diameter of coils is
approximately 610 mm for hot-rolled grades, and approximately 508 mm for cold-rolled grades.
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 may exhibit welds or interleaves resulting from the removal of defective zones or from
the joining of several lengths to obtain the sizes of the coils required by the purchaser, if
agreed between the manufacturer and the purchaser at the time of enquiry and order. If
necessary, the marking of welds or interleaves may be agreed between the manufacturer and
the purchaser at the time of enquiry and order.
For coils containing repair 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 are substantially
flat and approximately perpendicular to the top face.
Products supplied in sheets shall not contain any welds.
6.3 Delivery condition
The product is normally supplied without insulation. By agreement between the manufacturer
and the purchaser at the time of enquiry and order, the product may be supplied with
insulation on one or both sides. If the p
...