FIELD: machine building; may be used in manufacture of steel parts of machines and tools with surface hardening. SUBSTANCE: method provides for manufacturing parts from structural medium-carbon sparingly alloyed steels with some allowance, their carbonitriding and subsequent heat treatment for hardening of diffusion layer and core, including hardening, low-temperature tempering and medium-temperature tempering which is carried out for parts from steel 40X at 400 C. EFFECT: higher fatigue strength of parts operating under conditions of multicycle loading due to increase of core metal ductility. 2 cl, 1 dwg, 1 tbl
