The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 12, 1977
Filed:
Oct. 20, 1975
Peter John Gill, Wolverhampton, EN;
GKN Screws & Fasteners Limited, Warley, EN;
Abstract
A self-drilling and self-tapping fastener, particularly suitable for use in relatively thick metal, which is made from a headed blank by a method including pressing into the cylindrical free end of the blank a pair of straight flutes, by dies which are closed together on a line which is acutely angled to both the leading and trailing walls of the flutes. The flutes are inclined in opposite directions relative to the screw axis and are positioned on opposite sides of the screw. The tip is machined off to a V-form, to provide a ridge angularly advanced about the axis of the screw relative to the cutting edges of the flutes. Further machining may remove metal from the sides of the drill point between the flutes to provide flats and the drill point may be turned to a circular cross-section to provide sharp well-supported cutting edges for improved wear resistance. The drill point may taper overall, being of smallest diameter adjacent the threaded fastener shank.