Punch and die for producing dimpled holes in sheet metal

摘要

The punch (1) has a cylindrical protrusion (13) which provides the cutting edge, and a flange (12) the face of which has a conical groove (11) adjacent to the protrusion and a flat outer section (16). The punch acts in conjunction with a die which has a matching conical collar, such that as the punch and die are brought together, a circular blank is sheared from the workpiece. The metal adjacent to the hole is then pressed to form a conical lip. Alternatively, the groove and collar can be incorporated in the die and punch respectively. The die can have a replaceable cutting insert and a removable base.