THREADED FASTENER

摘要

PROBLEM TO BE SOLVED: To provide a threaded fastener that is improved to be suitable for special purposes and materials by a creative lead form. SOLUTION: A threaded fastener 10 includes leads 18 and 20 having bosses separated from one another by bases along the thread crest. The lead-in and lead-out profiles of the bosses, and other features of the bosses and bases may differ from one another along the fastener shank. The lead-in and lead-out profiles may have linear and non-linear surfaces. The lead-in and lead-out profiles may have cutting edges angled toward the direction of propagation of the bosses. 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. COPYRIGHT: (C)2003,JPO