Surface roughness is a measure of the texture of a manufactured surface. Although there are many definitions of surface roughness, all of them are based on a statistical representation of the high frequency surface deviations (peaks and values) from the local mean surface height. Filtering is used to separate the high frequency texture data from lower frequency machining features.
Surface roughness can be measured using contact methods involving dragging a stylus across the part.
Surface Texture and Surface Roughness produced by such means as abrading, casting, coating, cutting, etching, plastic deformation, sintering, wear, erosion, etc. need to be controlled due to functional considerations in many specific applications. The Dimensional Inspection Lab of AES accurately measures Surface Roughness, Surface Texture and Surface Finish in accordance with ASME B46.1- among other international standards, JIS, DIN, ISO, etc. or to your specific drawing or special requirements.