Abstract: A spinning apparatus for decreasing by spinning a thickness of a portion of a tube material having a uniform thickness except at a first axial end portion is disclosed. The spinning apparatus includes a spindle-side chuck having a conical concavity and a mandrel. The mandrel has a mandrel-side chuck formed in a form of a conical convexity corresponding in configuration to the conical concavity of the spindle-side chuck and a cylindrical portion for supporting the tube material. The spinning apparatus further includes a spinning roll for decreasing the thickness of the tube material by pressing the spinning roll against the tube material when the tube material is supported by the cylindrical portion of the mandrel.

Abstract: A spinning apparatus for decreasing by spinning a thickness of a portion of a tube material having a uniform thickness except at a first axial end portion is disclosed. The spinning apparatus includes a spindle-side chuck having a conical concavity and a mandrel. The mandrel has a mandrel-side chuck formed in a form of a conical convexity corresponding in configuration to the conical concavity of the spindle-side chuck and a cylindrical portion for supporting the tube material. The spinning apparatus further includes a spinning roll for decreasing the thickness of the tube material by pressing the spinning roll against the tube material when the tube material is supported by the cylindrical portion of the mandrel.

Abstract: A method of manufacturing a tubular member having a non-constant thickness by ironing at least a portion of the tubular material. The ironing apparatus can have a punch and a die, and the die can have a convex and concave side surface opposing the punch. The method can include bending an axial end portion of the tubular material to form a bent portion. The tubular material can then axially engage the die at the bent portion, and then the punch can be moved relative to the die to iron at least a portion of the tubular material.

Abstract: A method of manufacturing a tubular member having a non-constant thickness by ironing at least a portion of the tubular material. The ironing apparatus can have a punch and a die, and the die can have a convex and concave side surface opposing the punch. The method can include bending an axial end portion of the tubular material to form a bent portion. The tubular material can then axially engage the die at the bent portion, and then the punch can be moved relative to the die to iron at least a portion of the tubular material.

Abstract: A lightened disk for a wheel has a flange having an axially inboard edge. The inboard edge includes a general portion which is located in a plane perpendicular to an axis of the disk. The flange portion has a thickness less than 90% of a thickness of a disk material at at least the general portion of the inboard edge. A method for manufacturing a lightened disk for a wheel includes a drawing step during which the flange portion is drawn such than the flange portion has a thickness less than 90% of a thickness of a disk material at at least the general portion of the inboard edge.

Abstract: A lightened disk for a wheel has a flange having an axially inboard edge. The inboard edge includes a general portion which is located in a plane perpendicular to an axis of the disk. The flange portion has a thickness less than 90% of a thickness of a disk material at at least the general portion of the inboard edge. A method for manufacturing a lightened disk for a wheel includes a drawing step during which the flange portion is drawn such than the flange portion has a thickness less than 90% of a thickness of a disk material at at least the general portion of the inboard edge.