ASTM B946-11

The surface finish of a component may be critical for certain applications, affecting properties such as wear resistance, fatigue strength, and coefficient of friction.

Surface finish may also be critical for component assembly or system performance. Dimensional fit and mating surface interaction may require certain surface finish requirements to meet performance specifications.

1.1 This test method covers measuring the surface finish of powder metallurgy (PM) products at all stages of manufacturing from green compact to fully hardened finished component.

1.2 This test method provides the definition and schematic of some common surface finish parameters (R_a, R_t, and R_{z ISO})

1.3 The values stated in 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.

1.4 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 to determine the applicability of regulatory limitations prior to use.