Patent ID: 6990722

Claim:
A method of securing a fastener to a work piece with a tool having at least a rod and a mandrel, the tool controls the cooperation between the rod and the mandrel wherein the mandrel is concentrically located and axially displaceable relative to the rod, the mandrel having a tapered segment, the tapered segment extending between a reduced perimeter section and a cold working perimeter section, the method comprising: engaging a first portion of the fastener with a complementary portion of the rod; inserting the fastener into an opening in the work piece, the first portion of the fastener being positioned on a blind side of the work piece, an opposing portion of the fastener being positioned on an access side of the work piece and an intermediate portion having a length substantially equal to a thickness of the work piece; moving the tapered segment of the mandrel into contact with the opposing end of the fastener, a region of the reduced perimeter of the tapered segment at least partially positioned within an opening in the fastener while the cold working perimeter remains located slightly outside the opening in the fastener; seating the mandrel against the opposing end of the fastener; axially drawing the rod from the blind side toward the access side of the work piece in an amount sufficient to cause buckling in a region of the fastener, the buckled region of the fastener forming a flange on the blind side of the work piece; driving the cold working perimeter and the tapered segment of the mandrel through the opening in the fastener; and radially expanding the intermediate portion of the fastener between the blind side and the access side of the work piece with the cold working perimeter section of the mandrel.