Development of new steels in mechanical engineering to create alloys with predetermined properties that can minimize material and labor costs during their processing. Optimization of the chemical composition of the alloy based on the analysis of the impact of complex alloying on the structure and consequently on the manufacturability of steel. This will reduce the level of internal intensities in the heat treatment process. Based on the analysis of existing trends in mechanical engineering, it is established that the complexity of modern parts of gearweels imposes on the material increasing technological requirements for stamping, machinability, weldability, hardenability, cementation and gouging in the hardening process which explains the need for alloying steel via a certain group of chemical elements. The influence of different compositions of steels for gearweels on the level of internal intensities occurring in parts during heat treatment is studied. The optimal composition of complex-alloyed cementing steel is established.