This practice explains the procedure for identifying standard grades and types of flat-rolled electrical steels in ASTM electrical steel specifications. This practice applies to flat-rolled magnetically soft irons and steel such as low-carbon steels and alloys of iron with silicon, aluminum, and so forth produced to a specified thickness and maximum value of core loss. These designations are intended to replace the old AISI M designations which are no longer supported. The practice also has a cross-reference between thickness and electrical sheet gage number.

1.1 This practice covers the procedure for designating (within ASTM specifications) standard grades of flat-rolled electrical steels made to specified maximum values of core loss. This practice applies to magnetically soft irons and steel (low-carbon steels and alloys of iron with silicon, aluminum, and so forth) where a core loss measurement at a stated peak value of alternating induction and a stated frequency, such as 15 kG (1.5 T) and 60 Hz, is normally used to grade the material. This practice also applies when some other property is specified (or a different induction or frequency, or both) as the limiting characteristic, provided the material also meets all the requirements of the ASTM specification.

1.2 Individual specifications that are in conformity with this practice are Specifications A 677, A 683, A 726, A 840/A 840M, and A 876.

1.3 The values stated in customary (cgs-emu and inch-pound) units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.