Self-attaching female fasteners and method of forming female fastener elements

Abstract

A method of forming a female fastener including rolling a body portion strip having a midportion and flange portions on opposed sides of the midportion, piercing spaced openings through the midportion, cutting the strip to length between the openings, cold forming a separate generally cylindrical pilot portion having a length greater than the width of the midportion and a diameter greater than the opening through the midportion, preferably including radial splines, and press fitting the pilot portion through the opening in the midportion. The self-attaching female fastener thus includes a rectangular body portion and a generally cylindrical pilot portion having an end face spaced above a plane of the midportion and may be formed of a harder metal than the body portion.

1 - 16 . (canceled)  
   
   
       17 . A self-attaching female fastener, comprising: 
 a generally rectangular body portion including flange portions on opposed sides of said body portion and a midportion between said flange portions having an opening therethrough; and    a separately formed, generally cylindrical pilot portion having an axial length greater than said midportion and a major diameter greater than said opening through said midportion of said body portion press fit through said opening having an end face spaced above a plane of said midportion.    
   
   
       18 . The self-attaching female fastener as defined in  claim 17 , wherein said pilot portion is formed of a metal harder than said body portion.  
   
   
       19 . The self-attaching female fastener as defined in  claim 17 , wherein said pilot portion includes a plurality of spaced radial splines having a major diameter greater than an internal diameter of said opening through said midportion and said midportion deformed radially inwardly between said spaced radial splines.  
   
   
       20 . The self-attaching female fastener as defined in  claim 19 , wherein said spaced radial splines include a generally cylindrical outer surface having an outer diameter greater than said internal diameter of said opening through said midportion and relatively inclined side walls.  
   
   
       21 . The self-attaching female fastener as defined in  claim 19 , wherein said spaced radial splines extend to said end face of said pilot portion.  
   
   
       22 . The self-attaching female fastener as defined in  claim 17 , wherein said opening through said midportion includes a first generally cylindrical opening through one face of said midportion adjacent said end face of said pilot portion and a second opening through an opposed face of said midportion coaxially aligned with said first opening having an internal diameter greater than said first opening, and said pilot portion having a radial flange portion adjacent one end thereof having a diameter generally equal to said diameter of said second opening received in said second opening.  
   
   
       23 . The self-attaching female fastener as defined in  claim 17 , wherein said flange portions each include an end face spaced above a plane of said midportion.