Patent ID: 6712708
Filing Date: 2004-03-30
Classification: B21H,F16B

Abstract:
A method for making a threaded screw for joining thin workpieces comprising:inserting a headed blank having a lobular body section between a pair of dies each having, respectively, a set of linear grooves and a tapered area at one side thereof adapted to be located directly adjacent to a head of the headed blank upon a circular tapered portion of the blank; applying compressive forces onto the headed blank from the pair of dies; moving one of the dies in a linear direction thereby causing the headed blank to roll between the pair of dies, a center axis of the blank thereby defining an oscillating path with respect to a spacing center line between the dies, the dies forming a set of threads on the body section and a threaded tapered root portion on the tapered portion by plastically deforming the headed blank; and wherein the tapered root portion is provided with threads that are substantially the same outer diameter as an outer diameter of threads on the body section.