1. In ausforming 40Kh, 40KhN, and 40KhNM steels by extrusion with various degrees of deformation a structure is obtained characterized by the varying degree of elongation of the grains. 2. Under the investigated conditions of ausforming by extrusion the optimum degree of deformation is 70%. Under these conditions there is little recrystallization. 3. The addition of molybdenum and chromium to constructional steels is desirable in ausforming by extrusion since it makes it possible to maintain the structure formed in hot plastic deformation even with large reductions.