Two-piece mandrel assembly for deforming

摘要

A hole expansion mandrel assembly for expanding holes through work pieces including a drive pin with a leading pulling section and a trailing driving shoulder; and a collet removably carried on the drive pin and abutting the driving shoulder where the collet has an expansion surface to enlarge the holes as the drive pin is used to force the collet through the holes. The drive pin may incorporate a fastener trailing the collet. The method of using the apparatus is also contemplated.