2. Various geometric deviations in the surface condition

A surface profile is the curve resulting from the intersection of the actual surface and a specified plane. This plane is perpendicular to the surface of the sample and generally oriented perpendicular to the direction of the machining marks. A surface profile, in addition to the nominal shape of the part, is composed of various geometric deviations (figure 1 ), to which different profiles correspond (table 3 ):

• P profile, primary profile (order 1 + 2 + 3 + 4), on which the structure parameters are defined, designated by a symbol beginning with the letter P, for example Pt, Pa, etc.;

• W profile, corrugation profile (order 2), on which the corrugation...