Entirety of all deviations on the actual surface from the geometrically ideal surface.
On viewing the surface, a differentiation is made between coarser and finer deviations. For exact differentiation the surface deviations are divided into six categories: the shape deviation (Figure G 13 a), the ripple (b) and the various roughnesses (c) that overlap to varying degrees (d) (DIN 4760).
On surfaces that must be sealed, the seals must be able to compensate for all surface deviations.
Figure G 13: Surface deviations