A torsion bar includes a central portion extending in an axial direction about a longitudinal axis. The torsion bar also includes a first end portion having a splined outer surface, the first end portion disposed proximate a first end of the torsion bar, the first end portion spaced from the central portion with a first annular groove extending circumferentially about the torsion bar.

A rack bar blank for a steering system includes a first region having a first diameter. The rack bar blank also includes a second region having a second diameter that is greater than the first diameter prior to formation of teeth on the second region and a ball screw thread on the first region.

Provided is a production method of an aluminum alloy forging for an automobile suspension having a disturbance affectable surface with not excessively notch-sensitive. The production method includes, as heat treatment processes, a solution heat treatment process, a quenching process, and an artificial age hardening process. The quenching process is performed by bringing a lower surface of the aluminum forging to be disposed on a ground side when assembled to the automobile into contact with water before an upper surface of the aluminum forging opposite to the lower surface is brought into contact with the water.

A method produces a synchronizer ring for a synchronizing device in which blocking teeth extending radially outwards or radially inwards are produced by a forging method. The blocking teeth each have a flank portion and two oblique top flanks merging into a common top ridge. A depression is formed on the rear side of a blocking tooth opposite the top ridge.

A method is used to forge an outer joint member of a constant velocity universal joint. Track grooves of the outer and inner joint members each have an arc-shaped ball raceway center line having a curvature center that is not offset in an axial direction with respect to a joint center. The forging method includes performing ironing by press-fitting a cylindrical portion of one end of a shaft portion of a pre-processing material of the outer joint member including the shaft portion and the cylindrical portion into a die hole of a die while a punch set that is radially expandable and contractable is fitted to an inner peripheral surface of the cylindrical portion. The punch set includes punches and a punch base to guide the punches to enable advancing and retreating. Each of the punches has a pair of forming surfaces for forming the adjacent track grooves.

A forging method for a shaft member includes preforming at least one of a plurality of enlarged diameter portions to obtain a semi-finished member, and forming a remainder of the enlarged diameter portions in the semi-finished member using a mold. The mold includes a punch, split dies, and a workpiece receiving member. The forming of the remainder of the enlarged diameter portions includes allowing the semi-finished member having the at least one of the enlarged diameter portions to be placed on the workpiece receiving member, cramping the semi-finished member in its radial direction by closing the split dies, and filling the semi-finished member into forming surfaces of the split dies by the pressure applied by the punch under the state in which the semi-finished member is cramped.

A rack may include a toothed portion having a toothing, and a shaft portion having a threaded portion with a coaxial thread that has a thread length in an axial direction of a longitudinal axis. Separate segments comprising at least one in each case bar-shaped toothed segment and one shaft segment are provided, are aligned on the longitudinal axis, and are connected to one another at a joint. A method for producing the rack may involve providing a shaft raw material piece having a piece length that is a multiple of a shaft segment length, generating a thread that is continuous in a longitudinal direction on the shaft raw material piece across a multiple of the thread length to produce a threaded semi-finished product, cutting to length a threaded segment from the threaded semi-finished product, providing a toothed segment, and joining the threaded segment to the toothed segment.

Solid metal protrusions are formed by a method including: clamping and fixing the metal workpiece with a support die and a pressure die; pressing each cross section of an outer peripheral end parts of the metal workpiece fixed with the support die and the pressure die at a temperature lower than a softening point of a metal used as the metal workpiece from a direction perpendicular or oblique to an upright direction of the protrusions to be formed on one surface of the metal workpiece by press molding using a pressing die or a pressing jig; undergoing plastic flows of metal into through-holes formed as recessed parts that serve as female molds for forming the protrusions in at least one of the support die and the pressure die; and forming solid protrusions on the surface of the metal workpiece.

A method of manufacturing a torsion bar is provided. The method includes cutting a stock torsion bar material to a desired torsion bar length to form the torsion bar. The method also includes forming a first end portion by removing material from the torsion bar to form a first annular groove extending circumferentially about the torsion bar. The method further includes forming a second end portion by removing material from the torsion bar to form a second annular groove extending circumferentially about the torsion bar.

Processes are disclosed for forming beryllium-copper metal rings having a fine and uniform grain structure. A raw BeCu casting is pre-forged and turned to form a BeCu billet. The BeCu billet is subjected to various heat treatment and cooling cycles to obtain/maintain combinations of advantageous material properties. Generally, the BeCu billet is preheated, hot worked via forging, heated again, hot worked again via ring rolling followed by air cooling, solution annealed followed by quenching, and heated a final time followed by air cooling.