This test method covers a means of testing the interlaminar resistance of electrically insulating coatings as applied to adjacent laminations of flat-rolled electrical steel, under predetermined conditions of voltage, pressure and temperature. It indicates the effectiveness of surface coatings on electrical sheet steels for limiting interlaminar losses in electrical machinery. The interlaminar resistance is measured directly in units of resistance (k). This test method is particularly useful for, but not limited to, electrical steels coated with inorganic insulating coatings. 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. The values and equations stated in customary (cgs-emu and inch-pound) or SI units are to be regarded separately as standard. Within this standard, SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with this standard.