Abstract: A structure for a housing for an axle assembly and method for manufacturing same is disclosed. The housing includes a tube which is formed by casting. The tube is cast having a brake flange, a spring seat, a shock absorber pad, and an outer end for mounting wheel bearings, all of which are integrally formed therewith. The tube is generally hollow and cylindrical in shape, but is formed having an outer circumferential surface which is generally circular in shape and an inner circumferential surface which is generally oval in shape. Thus, the wall thickness of the tube is not uniform about the circumference thereof. Rather, the wall thicknesses of the upper and lower portions of the tube are somewhat greater than the wall thicknesses of the side portions thereof. The wall thicknesses of the upper and lower portions of the tube are sized to accommodate vertically oriented loads induced therein which are generally larger than horizontally oriented loads which are normally encountered in use.

Abstract: The present invention relates to a method of friction or inertia welding first and second metal components wherein one of the components is provided with an interface surface having a generally convex configuration, and the central portion of the convex-shaped surface is provided with an axially extending raised button. The convex-shaped surface and the raised button are simultaneously formed during a forging operation. The raised button ensures that, during the friction welding operation, the initial contact and friction heat build up will occur at the center of the interface surfaces.