Abstract: A method of case hardening surfaces of steel parts insures the presence of a relatively high percentage of untempered martensite within a case hardened depth of at least ten thousandths of an inch. The untempered martensite provides for a Rockwell C surface hardness in the range of 59 to 68, and promotes greater resistance to abrasion and deformation. The method also creates compressive stresses in the surface case hardened depth, and thus measurably enhances the fatigue life of the latter surface as a contact bearing member. The method includes the completion of all conventional metal removal operations on the part including finish machining steps prior to heat treatment thereof.