This study includes an experimental work to determine the effect of dilution on Hardfacing welding of clinker hammer crusher. In this work, samples have been prepared from the same metal type of hammer’s, of which is X120Mn12. Then the samples had been hardfaced using deferent kind of hardfacing Shielded Metal Arc Welding electrodes, and using deferent welding parameters (current, polarity), the calculation and measuring of dilution had done and then performed the hardness tests, wear tests, and their relation with dilution. This study showed that the reduction of heat input decreases dilution as the hardness of hardfaced samples increases and wear decreases. Direct current electrode positive (DCEP) increase dilution as the hardness of hardfaced samples decreases and wear increases, but the quality of the welding became better. Results showed that percentage of chromium and carbon in electrodes have positive effect on hardness.