Disc specimens manufactured from commercial bearing rollers (AISI 52100 steel, 62−63 HRC) in initial state and after pre-treatment by pulsed magnetic field (PMF) with a magnetic field strength of 1−7 MA/m were tested with sunflower oil using pin-on-disk apparatus. According to the obtained results the treatment causes a reduction in the coefficient of friction and wear. To explain the results, nano- and microhardness tests as well as optical and atomic force microscopy were used. Reasons of the effect of PMF on the friction and wear were discussed.