US Patent 7866759 Tubular axle housing with varying wall thickness

A method for manufacturing a one-piece axle tube housing with localized sections of increased wall thickness includes providing a tube blank, inserting a mandrel having a reduced diameter profile, passing the tube through an extrusion die to conform the tube to the shape of the mandrel; and extraction of the mandrel from the tube to cause outward deformation of the tube at specific locations. A further reducing step may be used to form the final desired profile, including reduced inner and outer diameters along sections of the axle tube housing.