US Patent 7421875 Cold-headed standoff

A process for cold forging a metal fastener such as a self-clinching standoff includes a punch and die set at the final head trimming station which produces the shear burr only on the underside of the fastener head where it is not visible after installation. A knock-out pin which is reciprocal within the bore of the punch forcibly ejects the fastener through a passage in the die to a point beyond an opposite side of the die. A stripper sleeve which is reciprocal about the outside surface of the punch then moves from a retracted position over the end of the punch pushing a residual scrap ring from around the outside of the punch.