An Experimental Work on Tool Wear Affected by Die Clearance and Punch Hardness

Die clearance is a widely known parameter affecting both tool life and edge quality of parts in blanking operations. Selecting the optimum punch-die clearance can give a longer tool life and better product quality by minimizing tool wear. In experimental studies, the effects of cutting die clearance and punch hardness on the punch edge and face wear were investigated. AISI D2 cold work steel with 50, 55 and 60 HRC-hardness punches was used as tool material. Three different cutting die clearances 3, 5 and 8% of sheet thickness were used. A modular punch-die set was prepared, and 2000, 4000, 6000 and 8000 samples are pressed. The results of the experiments showed that the punch edge and face wear decreased with increasing punch hardness and that smooth-sheared parts are strongly dependent on the clearance.