Patent ID: 7124492

Claim:
A method of attaching a fastener element to a panel, said fastener element including a shank portion, a first radial flange portion integral with and coaxially aligned with said shank portion having a diameter greater than said shank portion, and a second radial flange portion integral and coaxially aligned with said first radial flange portion having a diameter greater than said first radial flange portion, said second radial flange portion including an annular end face adjacent said first radial flange portion having a plurality of ribs projecting from said annular end face, said method comprising the following steps: forming an opening in said panel having a diameter at least equal to said diameter of said first radial flange portion and less than a diameter of said second radial flange portion; inserting said barrel portion and said first radial flange portion through said opening in said panel and locating said annular end face of said second radial flange portion opposite one face of said panel; driving said annular end face of said second radial flange portion against said one face of said panel and driving said ribs into said one face of said panel, preventing rotation of said fastener element relative to said panel; and driving an annular die surface against an opposed face of said panel, thereby deforming said panel radially inwardly beneath an overlying portion of said second radial flange portion, preventing withdrawal of said fastener element from said panel.