In this study X40CrMoV5 1 [H13] hot-work tool steel and C1030 plain carbon steel were welded to each other by using flash butt welding. Post weld normalization heat treatment was applied to one group of the test specimens welded under 2 bars of upsetting pressure and 1.6, 1.8 and 2 s of upsetting current times. Test results demonstrated that the highest hardness values obtained of the weld zone on C1030 side and the coarse grained zone on H13 side but with increasing upsetting current time there was a decrease in hardness values in the same zones of the specimens without heat treatment. Normalization heat treatment applied after welding caused a decrease in hardness and tensile strength values. (C) 2006 Elsevier Ltd. All rights reserved.