In this study, some mechanical properties of borided and unborided four steels were investigated. Boronizing of steels was performed by powder pack method at 1210 K for 4 h. The hardness of borides, boride layer thickness and room temperature tensile properties were measured and it was observed that hardness and tensile properties strongly depend on chemical composition of steels. In addition, the effect of a notch on impact behavior was examined by conducting the Charpy tests on borided and unborided steels. The greatest notch toughness was found for a steel AISI 316 with a microstructure consisting of different C, Ni and Cr chemical composition compared to AISI 1040, 1045 and 4140 steels.