Surface finish

[1] It comprises the small, local deviations of a surface from the perfectly flat ideal (a true plane).

Surface texture is one of the important factors that control friction and transfer layer formation during sliding.

Considerable efforts have been made to study the influence of surface texture on friction and wear during sliding conditions.

Sometimes, stick-slip friction phenomena can be observed during sliding, depending on surface texture.

The latter process may be grinding (abrasive cutting), polishing, lapping, abrasive blasting, honing, electrical discharge machining (EDM), milling, lithography, industrial etching/chemical milling, laser texturing, or other processes.

Lay is the direction of the predominant surface pattern, ordinarily determined by the production method used.

Contact methods involve dragging a measurement stylus across the surface; these instruments are called profilometers.

[4] Any given manufacturing process is usually optimized enough to ensure that the resulting texture is usable for the part's intended application.

Generally, these two characteristics are linked: manufacturing processes that are dimensionally precise create surfaces with low roughness.