SWAGE TYPE FASTENER WITH LOW SWAGE LOAD

摘要

A two piece fastener system for including a pin member (12) and a collar (14) having an optimized strenght with the materials of the pin member (12) and collar (14) having a predetermined shear strength ratio; the collar (14) has a preselected excess volume to provide a desired 'overpacking' condition and is of a size whereby after swage it will define a minimum wall thickness; the collar (14) has an outer surface (70) with a contour which in combination with a preselected excess volume results in a reduction in load required to swage the collar (14) and with a pull type fastener providing a breakneck groove (38) of reduced strength whereby severance of the pintail (40) will occur at a reduced load resulting in a reduction in shock or ghost load applied to workpieces including those of a plastic or composite material.