Patent ID: 7704151

Claim:
A method of forming self-attaching female fasteners, comprising the following steps: rolling a metal section and forming a desired cross-section of a self-attaching female fastener, said section including a central pilot portion and flange portions on opposed sides of said central pilot portion, said central pilot portion and said flange portions extending along a longitudinal axis of said section; punching generally cylindrical bores through said central pilot portion equally spaced along said longitudinal axis; and punching pairs of configured openings through said section, said openings of each of said pairs opposing each other about said longitudinal axis and equally spaced from said bores along said longitudinal axis, each of said opening extending into said central pilot portion and one of said flange portions, each of said openings including convex arcuate pilot surfaces extending into said central pilot portion and one of said flange portions and eliminating sharp corners of said central pilot portion.