IEC 60404-9:2018 specifies the measurement and test methods for the determination of the following geometrical characteristics of electrical steel strip and sheet:
–    edge wave (wave factor);
–    residual curvature;
–    edge camber;
–    deviation from the shearing line (internal stress);
–    burr height.
This document applies to electrical steel strip and sheet intended for the construction of magnetic circuits and corresponding to Classes B2, C21, C22 and C23 of IEC 60404-1.
This edition includes the following significant technical changes with respect to the previous edition:
a. revision of terms and definitions;
b. specification of the length of test specimens for the determinations of edge wave (wave factor) and edge camber;
c. addition of the horizontal method for the determination of residual curvature, and a note that informs about a safety concern of the vertical method;
d. clarification that the burr height was characterized by the maximum value;
e. addition of the measuring procedure using a hand-held micrometer to determine the burr height.