ISO 4970:1979

Steel — Determination of total or effective thickness of thin surface-hardened layers

Specifies the micrographic method and the microhardness measurement method. Applies to thin surface layers, with thicknesses of less than or equal to 0.3 mm, obtained, for example, by mechanical (shot blasting, shot peening, etc), thermal (flame or induction hardening, etc) or thermochemical (carbonitriding, carburizing and hardening, etc) treatment. It is not applicable to thin surface layer which are not continuous with the basis metal.