American Society for Testing and Materials (ASTM). Current edition approved Aug. 1, 2005. Published September 2005. 7 p. This practice describes the nondestructive measurement of the dry film thickness of nonmagnetic coatings applied to the surface of ferrous metals using magnetic gages and the nondestructive measurement of the dry film thickness of electrically nonconductive, nonmagnetic coatings applied to the surface of nonferrous metals using eddy current gages. This practice is intended to supplement the manufacturers’ instructions for the manual operation of the gages and is not intended to replace them. It includes definitions of key terms, reference documents, the significance and use of the practice, the advantages and limitations of coating thickness gages, and a description of test specimens.