In engineering practice it is necessary to know which plastic or elastic deformation of asperities of the contact surfaces is the predominant. For determination of the contact type we propose to use an original contact criterion (CC). It was experimentally proved that at a normal exploitation regime an elastic deformation of asperities (which provides minimum wear intensity) occurs when CC > 1.7. The proposed CC is suitable for engineering calculation and is correct for all types of roughness. Using of CC allows selecting roughness parameters, material and technological processing on drawing with prediction of the type of the contact for sliding wear surfaces. CC can be used, for example, in calculation of the intensity of linear wear, which should be determined separately for the plastic and elastic contact.