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.