The extreme pressure properties of ferrous metals can be increased by coating the metal with iron sulfide or chloride or mixtures thereof then heat treating the coated metal at a temperature in the range of 900*-2,000* F. for 1/2 to 24 hours. When metal Falex pins and jaws are treated in the above fashion they have longer running times, i.e., up to 11 times, than untreated pins and jaws under the same conditions in a standard Falex testing apparatus.