Method of forming a fastener

摘要

An improved method of forming a fastener having a head and a shank includes the step of heating one end of a piece of barstock. A ring is then telescopically slid onto the cold end and moved toward the hot end of the barstock. Due to thermal expansion of the hot end of the barstock, the ring interferes with the hot end of the barstock. The ring is then engaged by a pair of dies and the barstock is forced further through the ring to accurately position it relative to the ring. The dies are then pressed against the barstock and the ring to grip the barstock and hold it against axial movement relative to the ring. The dies cooperate with the ring to form a die cavity. The hot end of the barstock extends into the die cavity. A header hot works the metal of the barstock to press it against an end surface of the ring and against side surfaces of the dies to shape the head end of the fastener. The header is then withdrawn, the dies are separated and the ring is removed from the shank of the fastener.