Method for making a fastener

摘要

A threaded fastener includes a lead having bosses separated from one another by bases along the thread crest. Two such leads may be formed such that lead-in profiles for of one lead are disposed at locations corresponding to locations of lead-out profiles for the other lead. The lead-in and lead-out profiles of the bossed, and other features of the bosses and bases may differ from one another along the fastener shank. The boss profiles may be selected to reduce insertion torque and to provide excellent resistance to pullout. The fastener may be formed by roll threading via a tool made by a plunge EDM process.