Friction stir welding

A method of friction stir welding of members, particularly for joining of extruded assembled shapes, comprising steps of urging and securing the assembled members towards each other, entering the assembled members along the joining line by a probe of material harder than the material of joined members under rotating movement which generates a frictional heat, thereby creating a plasticised region in the adjacent members' material, the method further comprising a homogenization of the resulting weld seam ensured by an enhanced flow of plasticised material both perpendicularly and vertically to the longitudinal extension of the adjacent assembled members by exposing the created plasticised material to a perpendicular pressure along the surface of the members and causing simultaneous material flow along the probe pin in the vertical direction allowing the plasticised material to solidify behind the probe.