In this study, the dissimilar friction welding of a medium C45 (AISI 1040) carbon steel and powder metallurgically produced tool steel 1.3344PM (AISI M3:2) (Vanadis 23) was investigated. Round bars of 11,3 mm diameter in hot-rolled and normalized condition were used. The welding experiments were carried out by an industrial friction welding machine with different friction welding parameters determined from pre-experimental studies and literature. Post weld heat treatment (PWHT) at 650 °C for 4 hours was also applied. Variations of microhardness were measured along the rod axis with 50g test load in all joints and the welding zones were examined with light optical microscope (LOM) and scanning electron microscope (SEM) including both as-welded and PWHTed samples.