What is the most common type of surface finish called?

The most common type of surface finish referred to in the context of manufacturing and material processing is roughness. Roughness specifically quantifies the small, finely spaced deviations from a perfect smooth surface. It is a key parameter that affects various characteristics of a material, such as friction, wear resistance, and aesthetic appearance.

In many industrial applications, the roughness of a surface is critically important, as it can influence how well the surface interacts with other components, such as in assembly or when subjected to lubrication. Higher roughness can increase surface area, which may enhance certain properties like adhesion or bonding, while lower roughness is often desired for applications requiring smoothness, such as in bearings and sliding surfaces.

While terms like smoothness and gloss are related to surface characteristics, they do not specifically denote types of surface finish in the same technical manner as roughness does. Smoothness is more about the absence of imperfections, and gloss relates to the optical reflection off a surface. Peening, on the other hand, refers to a specific treatment process used to improve the surface properties, particularly fatigue strength, through deformation and does not classify a surface finish type.