Patent ID: 8328483

Claim:
A blind rivet system comprising: at least two workpieces defining a tool-facing surface and an opposite blind surface; an axially extending hollow tubular body having a tail end at one end and a pre-formed, hollow and radially enlarged flange at the other end adjacent said tool-facing surface; and a mandrel having a stem which extends co-axially though said body and having an enlarged head adjacent said tail end of said body, said head having an outer diameter greater than an inner diameter of said body; wherein said mandrel has a conical shoulder extending between said outer diameter of said head and said stem, and said stem having a weakened region adjacent said conical shoulder; wherein said mandrel upsets said tail end so that said tail end is expanded into a counter-sunk region of said blind surface such that said expanded tail end does not extend substantially above said blind surface; wherein a cross-sectional wall thickness of said preformed radially enlarged flange is greater than a cross-sectional wall thickness of said hollow tubular body both before and after setting; and wherein said head diameter is between 4% and 9% greater than an outer diameter of said body.