Patent ID: 6581819
Filing Date: 2003-06-24
Classification: B23K,B61D,E04C,Y10T

Abstract:
A friction stir welding method comprising the steps of:preparing (a) a first member having a first part and a raised portion, protruding beyond said first part from one side in the direction of thickness, at an end part of said first member, and (b) a second member to be welded to said first member, said first part of said first member having a surface and said second member having a surface; abutting said first member, where said raised portion of said first member is located, against said second member to be welded to each other, to provide an abutting portion, said surface of said first part of said first member being substantially coplanar with said surface of said second member; and friction stir welding said first member and said second member to be welded from said raised portion side of said first member, said friction stir welding being performed by moving a rotary tool along said abutting portion of said first member and said second member, said rotary tool extending from said raised portion side of said first member, said rotary tool having a first portion of a first diameter and a second portion of a second diameter smaller than said first diameter, wherein during said friction stir welding said second portion of said rotary tool extends into said raised portion and said first part of said first member, and wherein during said friction stir welding material of said raised portion fills any gaps, between said first member and said second member, which exist when said first member abuts said second member.