Patent ID: 7341413

Claim:
A self piercing blind fastener comprising: a mandrel; an elongate cylindrical shell mounted on an elongate stem of said mandrel so as to extend co-axially about a central elongate axis of said blind fastener; said shell having a radially extending flange at one end thereof and a tail end at the opposite end for insertion through a workpiece; said mandrel having a mandrel head in operative engagement with said tail end of said cylindrical shell for transmitting force thereto during setting of said fastener; and a longitudinally extending indenting member extending co-axial with and away from said tail end of said cylindrical shell, said indenting member having a cross sectional area less than the cross sectional area of an outside surface of said cylindrical shell, wherein said indenting member has an end face extending at least partly perpendicular to said elongate axis, wherein said indenting member comprises a longitudinally extending side wall forming a step portion extending from a periphery of said end face towards said tail end of said cylindrical shell.