Patent ID: 6786827
Filing Date: 2004-09-07
Classification: B25B,F16B,Y10T

Abstract:
A punch for forming a head of a recessed head threaded fastener comprising:a punch body having a face and an integral nib protruding from the face, the nib being the complement of the shape of the fastener recess and the face being of complementary shape to that of the intended screw head; the nib including a central core and a plurality of blades that extend radially and outwardly from the core, each of the blades having a pair of sidewalls and an end wall, the end wall being inclined upwardly and outwardly from the outer region of the core; the blades, at their upper ends merging into the face of the punch to define an integral structure; at least one of the side walls of one of the blades being configured to define a raised region, extending from the end face of the punch downwardly toward the end wall of the blade, the raised region being defined by at least one riser extending along the juncture of the raised and unraised portions of the blade sidewall, each of the raised surface and risers having a positive draft angle.