Controlled flow of displaced material in self-pierce fastening

摘要

A self-piercing tubular fastener (13) is applied to a workpiece (9, 11) by means of a setting die (1) which is formed with a radially inner cavity (17) and a radially outer cavity (5) surrounding the radially inner cavity such that a first part of the material displaced as the fastener (13) penetrates the workpiece flows into the radially inner cavity in the setting die whilst a second part of the displaced material flows into the radially outer cavity.