be tapered if desired similarly the point of attachment of web portion 13 to main portion 11 can be varied in accordance with the design of the wheel to be made extrusion 12 will be made in a length of at least equal to the circumference of one wheel but generally it will prove more feasible to extrude it in longer lengths a multiple of the circumference of a single wheel and cut pieces to the desired length after being subjected to the usual straightening process by stretching the extrusion will be cut to the circumferential length of one wheel and curved so that the two ends of the extrusion are substantially abutting these two ends will then be joined by any suitable method welding being preferred although conventional molten metal welding or electron beam welding can be used pressure welding particularly at ambient temperature is preferred because heat is not used ambient temperature pressure welding results in a much stronger joint than would be achieved with a molten metal welding operation in fact it has been found that the metal in cold pressure welded joints has substantially as good properties strength elongation etc as the metal which has not been subjected to the cold welding operation cold pressure welding.