Surface Finish (Ra)

Measurement of the average roughness of a surface. NOTE 1 It is expressed in micrometres (μm). NOTE 2 All of the surface finishes given in this American National Standard are to be considered maxima.

Source: API SPEC 16A, Specification for Drill-through Equipment, Third Edition, June 2004 (Errata/Supplement November 2004). Global Standards

Comments are closed.