Plasma electrolytic treatment (PET) is often used to improve the functional properties of the material by formation a thick coatings up 500 microns [1]. The advantages of PET include high processing speed, low cost, the possibility of obtaining promising nanoscale structures, the convenience of local processing, the continuous updating of saturating media, and etc. Plasma-electrolyte hardening of parts is used to quickly saturate the treated surface with light elements (carbon-cementation, nitrogen-nitriding, boron-boriding, and their combinations) to increase hardness, wear resistance and corrosion resistance.  PET of metals and alloys with light elements are studied by numerous scientific teams. It is possible to divide the researchers of electrolytic-plasma treatment into two groups, studying the anodic and cathodic realization of this treatment. Most of the publications are related to materials science and chemical-thermal processing. The conditions of high-speed carburization, nitrocarburization, nitriding, boriding and borocentering of structural steels from electrolytes of various composition are published.  One of the most important advantages of PET is that due to a very short time it is possible to increase the surface hardness and wear resistance several times exceeding the initial values. It is possible to increase the wear resistance of coatings produced by PET more than 100 times, based on the ball-on-disk techniques.  Testing the wear resistance of parts directly under real conditions is less widely described in the literature, since basically all publications are limited to model studies of wear resistance according to the ball (pin) -disk scheme.  The present work is devoted to the investigation of the possibilities of increasing the wear resistance of the screw-nut friction pair after various types of PET.  The wear resistance of the pair after carburizing, borading, nitriding, borazotation of both the screw and the nut has been studied. The study of wear resistance was carried out both for one element of the pair after treatment, and after treatment of two elements of the pair.  The data obtained indicate an increase in mass wear, and an increase in the operating time of the screw-nut pair, more than 60 times after the EPO.