Patent ID: 7854362

Claim:
A multi-shouldered friction stir welding tool comprising: an integral shank-pin unit having a plurality of pin portions on the shank-pin unit, wherein the plurality of pin portions for driving into a plurality of joints to perform a friction stir welding operation on the corresponding plurality of joints and, wherein a shank portion of the shank-pin unit is for attachment of an optional axial tension rod, a plurality of friction stir welding modules, each of the friction stir welding modules comprising: a pair of shoulders that is connected to the shank-pin unit where each shoulder has a distal end and a proximal end, where the proximal end of each shoulder faces the pin portion of the shank-pin unit, whereby the shoulder and pin(s) rotate in unison; and a pair of split collars that is connected to the shank-pin unit and faces the distal end of each shoulder; wherein the plurality of friction stir welding modules are connected to each other whereby the modules rotate in unison to simultaneously make a plurality of parallel welds and wherein each split collar has a threaded outer diameter and a threaded inner diameter that is connected to the shank-pin unit by threading the outer diameter of the collar onto threads on an inner diameter of the shoulder and threading the inner diameter of the collar onto threads on an outer diameter of the shank-pin unit.