Abstract: A method and apparatus for welding a first workpiece which is to be joined to a second workpiece, with said first workpiece extending within or through the second workpiece. The apparatus includes a rotatable workpiece drive member, a workpiece holding fixture for securing at least one other workpiece in position relative to the first workpiece and a radial support for the first workpiece that is separate and spaced from the drive member. Among the preferred embodiments disclosed for providing the radial support are a tailstock supporting sleeve arrangement, collet chucking, and roller type steady rests.

Abstract: A method and apparatus for mechanically expanding pipe of the type having a helical weld seam which includes a radially expandable die head assembly for incrementally expanding the pipe advanced over the die head and wherein the die head has a helical groove which corresponds to the helical weld seam of the pipe. Means are provided for advancing the pipe longitudinally over the die head assembly for incremental expansion and preferably for substantially simultaneously rotating the pipe to maintain the conformity between the die head groove and the helical weld seam of the pipe.