The development of manufacturing engineering leads to the bill of goods expansion that work in extreme conditions and are made of new steels and alloys. Unfortunately, the traditional technological methods are not able to ensure the necessary performance characteristics of parts surfaces. Diamond smoothening is a well-behaved technological method that allows to finely controlling the quality parameters of the layer surface. However, we consider that the physical processes that occur in the interface between the indenter and the hardened surface are not well understood. A deeper understanding of the physical processes occurring in the contact zone will expand the scope of surface hardening by smoothening. In our work, we tasking the physical boundary conditions in the contact zone between the hardening tool and part surface.