WG 1 - TC 68/WG 1

IEC 60404-1:2016 is intended to classify commercially available magnetic materials. The term "magnetic materials" denotes substances where the application requires the existence of ferromagnetic or ferrimagnetic properties. The classification of magnetic materials is based upon the generally recognized existence of two main groups of products:
- soft magnetic materials (coercivity less than or equal to 1 000 A/m);
- hard magnetic materials (coercivity greater than 1 000 A/m). This edition includes the following significant technical changes with respect to the previous edition:
a) Removal of all tables and values describing typical properties of the material to be consistent with the aim of the document to be a classification and not a specification.
b) Enlargement of the Ni content for the classes E1 and E3.
c) Enlargement of the Co content for the classes F3.
d) Addition of a new class: U5 bonded rare earth-iron-nitrogen magnets.

Establishes a classification of surface insulations for electrical steel sheet, strip and laminations according to their general composition, relative insulating ability and function. These surface insulations are either oxide layers or applied coatings. The purpose of this classification is to create a nomenclature for the various types of surface insulations and to assist users of surface insulations by providing general information about the chemical nature and use of the surface insulations. It is not the intent of this classification to specify insulation requirements in terms of specific values of surface insulation resistance. Such requirements are agreed between the purchaser and the steel producer, where applicable. The classification is used in conjunction with the various specifications for cold rolled electrical steels (see the standards in the IEC 60404-8 series in Clause 2).

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.

IEC 60404-8-4:2022 defines the grades of cold-rolled non-oriented electrical steel strip and sheet in nominal thicknesses of 0,35 mm, 0,47 mm, 0,50 mm, 0,65 mm and 1,00 mm. In particular, it gives general requirements, magnetic properties, geometric characteristics, tolerances and technological characteristics, as well as inspection procedure. The nominal thickness 0,47 mm applies to the grades for use at 60 Hz only. This document applies to cold-rolled non-oriented electrical steel strip and sheet supplied in the fully-processed state, i.e. the final annealed condition, in coils or sheets, and intended for the construction of magnetic circuits. This document does not apply to materials supplied in the semi-processed state. This edition includes the following significant technical changes with respect to the previous edition:
- modification of terms and technical requirements concerning geometrical characteristics to be consistent with IEC 60404-9:2018;
- insertion of Table 3 - Tolerances on nominal thickness;
- change of the length of test specimen for determination of geometrical characteristics from 2 m to 1 m.

IEC 60404-8-7:2020 defines the grades of cold-rolled grain-oriented electrical steel strip and sheet in nominal thicknesses of 0,20 mm, 0,23 mm, 0,27 mm, 0,30 mm and 0,35 mm. In particular, it gives general requirements, magnetic properties, geometric characteristics, tolerances and technological characteristics, as well as inspection procedures. This document applies to Goss textured grain-oriented electrical steel strip and sheet supplied in the final annealed condition in coils or sheets, and intended for the construction of magnetic circuits. The grades are grouped into three classes:
- conventional grades;
- high permeability grades;
- magnetic domain refined high permeability grades.
They correspond to Class C22 of IEC 60404-1.
This edition includes the following significant technical changes with respect to the previous edition:
- insertion of a third class of grain-oriented electrical steels for magnetic domain refined high permeability grades;
- introduction of the single sheet tester (SST) method as reference measurement method for this third class of material together with a conversion factor for transposition of the SST measurement results to equivalent Epstein values;
- update of the electrical steel range to take account of the current offers and demands of grades.

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.

Applies to magnetic material intended for the construction of magnetic circuits. These materials correspond respectively to classes C.21 and B.2 of IEC 60404-1: 2000. This standard defines the grades of cold-rolled electrical non-oriented non-alloyed (non alloyed steel is that steel the basic constituent of which is iron containing alloying elements in amounts smaller than the limiting values fixed by ISO 4948 1) or alloyed (alloyed steel is that steel the basic constituent of which is iron containing alloying elements in amounts equal to or greater than the limiting values fixed by ISO 4948 1) steel sheet and strip delivered in the semi-processed state, i.e. without final heat treatment, of nominal thicknesses given in Tables 1 and 2. It specifies general requirements, the magnetic properties, the geometrical characteristics and tolerances, technological characteristics as well as the inspection procedure.

Intended to classify commercially available magnetic materials. The term "magnetic materials" denotes substances where the application requires the existence of ferromagnetic or ferrimagnetic properties. The classification of magnetic materials is based upon the generally recognized existence of two main groups of products. - soft magnetic materials (coercivity less than or equal to 1000 A/m) - hard magnetic materials (coercivity greater than 1000 A/m) Within these main groups, the classification when appropriate recognizes the following characteristics: - the main allowing element and the metallurgical state and physical properties of the material; - when possible and convenient, the relationship between these characteristics is identified. A classification by specific areas of application cannot be applied to all materials because different materials can very often be used for the same application depending on the characteristics required.

Defines the grades of cold-rolled electrical non-oriented non-alloyed steel strip delivered in the semi-processed condition, that is without final heat treatment, of 0.50 mm and 0.65 mm nominal thickness. Specifies general requirements, the magnetic properties, the geometric characteristics and tolerances, technological characteristics as well as the inspection procedure. Applies to material intended for the construction of magnetic circuits.

Defines the grades of grain-oriented electrical steel sheet in nominal thicknesses of 0,23 mm, 0.27 mm, 0.30 mm and 0.35 mm. Gives general requirements, magnetic properties, geometric characteristics and tolerances, and technological characteristics, as well as inspection procedures. Applies to Goss textured grain-oriented electrical steel sheet supplied in the final annealed condition in sheets or coils, and intended for the construction of magnetic circuits.

Defines the grades of cold-rolled non-oriented electrical steel sheet and strip in nominal thicknesses of 0.35 mm, 0.50 mm, 0.65 mm and 1,00 mm. Specifies general requirements, the magnetic properties, geometric characteristics and tolerances, and technological characteristics, as well as the inspection procedure. Applies to materials supplied in the fully annealed condition intended for the construction of magnetic currents. Does not apply to semi-processed material.

Defines the grades of cold-rolled electrical non-oriented alloyed steel sheet and strip delivered in the semi-processed condition, that is without final heat treatment, of 0.50 mm and 0.65 mm nominal thickness. It specifies general requirements, the magnetic properties, the geometric characteristics and tolerances, technological characteristics as well as the inspection procedure. Applies to material intended for the construction of magnetic circuits.