Patent ID: 7121450
Filing Date: 2006-10-17
Classification: B23K,Y10T

Abstract:
1. A friction stir welding method, comprising: preparing plural members, each having projections at end portions of a plate that protrude toward a direction of thickness of the plate; butting an end portion of the plate against an end portion of an adjacent plate, wherein the thickness of the plate of at least one member is different from the thickness of the plate of another member, and a protruded height of the projections on the plates at a butt joint portion where the plate thickness is large is smaller than the protruded height of the projections on the plates where the plate thickness is small, and the protruded height of the projections on the plates at a butt joint portion where the plate thickness is small is larger than the protruded height of the projections on the plates where the plate thickness is large; and inserting rotary tools of the same size with the same insertion depth to the plates from the side having the projections, and performing friction stir welding.