Comparison of mechanical properties of medium carbon steel AISI 1040 for vanadium carbide coated (VCC) and boronized conditions has been studied by means of microhardness, tensile and impact tests. For the treated steels, the boriding and vanadizing processes have been carried out in the same conditions, i.e., at a temperature of 1210 K for 4 h. The thickness of diffusion layer has been measured as 5 pm and 100 mu m for the VCC and the boronized steels, respectively. In laboratory conditions, the VCC steels show considerably higher strength and surface hardening with respect to the untreated and the boronized steels. At the same time, Charpy V-notch impact tests have also been carried out for the steels with and without surface hardening. It is concluded that coating is effective in improving the mechanical performance of AISI 1040 steels.