Patent ID: 7383624

Claim:
A method of forming a sealed female fastener and panel assembly, said female fastener including an annular pilot portion having an annular end face, a bore extending through said pilot portion through said end face, an annular flange portion surrounding said pilot portion having an annular end face parallel to said end face of said pilot portion, and an annular groove in said flange portion having a bottom wall and relatively inclined side walls including an outer side wall and an inner side wall inclined radially outwardly from adjacent said bottom wall, said bottom wall defining anti-rotation features extending from said bottom wall and spaced from said inclined side walls, said method comprising the following steps: driving an annular lip of a die member against a panel engaging said annular end face of said pilot portion, said annular lip having an inner diameter less than an outer diameter of said annular end face of said pilot portion and an outer diameter less than an inner diameter of said outer side wall of said annular groove, thereby piercing a slug from said panel having a diameter less than said outer diameter of said annular end face of said pilot portion and forming an opening through said panel; continuing to drive said annular lip of said die member against a panel portion surrounding said opening in said panel and against an outer periphery of said annular end face of said pilot portion, thereby shaving an annular outer portion of said pilot portion generating an annular radial protrusion continuously against an inner portion of said panel portion; and continuing to drive said annular lip of said die member against said panel portion and said annular outer portion of said pilot portion and deforming said pilot portion against said bottom wall of said annular groove and said anti-rotation features being spaced from said inclined side walls, thereby deforming said panel portion radially inwardly and outwardly entrapping said panel portion in said annular groove and sealing said female fastener on said panel as said panel is deformed against said bottom wall to conform to the shape of said anti-rotation features thereby preventing rotation of said female fastener on said panel.