<p>ĉe article presents the results of experimental studies that establish the features of increasing the strength and wear resistance of steels aĜer thermocycling. ĉermocyclic treatment as a method of heat treatment is based on continuous accumulation ěom cycle to cycle of positive changes in the structure of metals. An important feature of the cycle is its intensity, the absence or the presence of short exposures, the optimal range of temperature changes. ĉe paper establishes the laws of the inĚuence of the temperature-time parameters of thermocyclic processing on the physicomechanical properties of tool steel and the technology of hardening machine parts due to the intensiėcation of diffusion processes, phase and structural transformations, which reduce the duration of heat treatment and improve the whole complex of mechanical properties, that is the reliability of machine parts. Based on theoretical and experimental studies, it has been established that the production of ultraėne grains contributes to an <br /> increase in the wear resistance of steels. When using thermal cycling, higher characteristics of mechanical properties were obtained, ěacture toughness increased by 1.5 times, and wear resistance increased by 1.9 times. ĉis is due to the nature of the resulting structure and the degree of grain reėnement.</p>