Patent ID: 6640414
Filing Date: 2003-11-04
Classification: B21J,B23K,F16B,Y10T

Abstract:
A method of attaching metal members, comprising the steps of:(a) placing the metal members in contact with each other; (b) providing a metal fastener having a central axis wherein: i) the metal fastener includes an elongated portion extending from a bottom surface of a head portion of the fastener; and ii) the elongated portion includes a topographically varying outer surface for forming a plurality of inflection sites along the elongated portion; (c) rotating the metal fastener about the axis using a rotary driving apparatus; (d) driving the metal fastener through the metal members during rotation of the fastener thereby inducing friction between the fastener and the metal members for locally melting the members to form a flowable material that flows into at least one of the inflection sites of the fastener and wherein the fastener is driven only partially through one of the members; and (e) allowing the flowable material to solidify within the plurality of inflection sites for attaching the members, the flowable material and the fastener together wherein: i) the metal members are at least partially attached to each other with an interference fit created by the topographically varying outer surface of the elongated portion; and ii) the solidified flowable material directly metallurgically bonds the metal members to each other.