Patent ID: 8636455

Claim:
An assembly installable in an opening of a workpiece, comprising: an outer member having a passageway; and a fastener movable through the passageway, the fastener including: a mandrel dimensioned to radially expand the outer member, a stem including an expansion portion and a propping portion, the expansion portion configured to radially expand the outer member after at least a portion of the outer member has been expanded by the mandrel, and a separable portion between the mandrel and the stem, wherein the mandrel has a maximum outer diameter that is greater than an outer diameter of the propping portion such that an initial interference fit between the outer member and the workpiece is produced as the mandrel expands the outer member and an installed interference fit between the outer member and the workpiece is maintained by the propping portion within the outer member, and a ratio of the initial interference fit to the installed interference fit is in a range of about 1.25 to about 3.