This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member...http://www.google.es/patents/US7114304?utm_source=gb-gplus-sharePatente US7114304 - Friction stir welding member
