To provide a method of manufacturing a shaft for a steering device, the shaft including a spline shaft part to be coupled with an input shaft, a stopper part to be coupled with an output shaft, and an intermediate shaft part that couples the spline shaft part with the stopper part. The method includes: a step of forming a hole part recessed in an axial direction from one end of a pillar-shaped material by forging; and a step of pressing the material in which the hole part has been formed into a die to perform drawing in a radial direction on a portion of the material at which the spline shaft part and the intermediate shaft part are formed, and prolonging a length along the axial direction of the hole part at the same time by forging.

To provide a method of manufacturing a shaft for a steering device, the shaft including a spline shaft part to be coupled with an input shaft, a stopper part to be coupled with an output shaft, and an intermediate shaft part that couples the spline shaft part with the stopper part. The method includes: a step of forming a hole part recessed in an axial direction from one end of a pillar-shaped material by forging; and a step of pressing the material in which the hole part has been formed into a die to perform drawing in a radial direction on a portion of the material at which the stopper part is formed and prolonging a length along the axial direction of the hole part at the same time by forging.

A method for manufacturing a gear toothing on a metallic workpiece and a tool device for calibration of a gear toothing inlet and/or a gear toothing outlet of a gear of the metallic workpiece. The method includes producing the gear toothing by forming manufacturing and performing a compression process to calibrate a gear toothing inlet and/or a gear toothing outlet of the gear toothing, wherein a gear tooth shape and a gear tooth length are adjusted during the compression process. The tool device includes a workpiece location for accommodating the workpiece, an axially movable die selectively engageable with the gear toothing, the die supporting the gear toothing and predefining the gear tooth shape to be adjusted on the gear toothing inlet and/or on the gear toothing outlet, and at least one axially movable compression ring which calibrates the gear toothing inlet and/or gear toothing outlet by a compression process.

A gear-tooth system can be produced on a component of a shaft/hub connection. The component can have a first axis of rotation and a gear-tooth system; wherein the gear-tooth system of the component comprises a plurality of teeth, disposed next to one another along a circumference direction, wherein a tooth interstice is disposed between two teeth, in each instance, and each tooth has a head region and a flank region, in each instance, between head region and a foot region disposed in the tooth interstice, wherein the tooth interstice has a tooth gap width in the flank region; wherein the gear-tooth system has at least a first region and subsequently a second region along an axial direction parallel to the first axis of rotation; wherein the first region has a first tooth gap width and the second region has a second tooth gap width, which is less in comparison.

A gear-tooth system can be produced on a component of a shaft/hub connection. The component can have a first axis of rotation and a gear-tooth system; wherein the gear-tooth system of the component comprises a plurality of teeth, disposed next to one another along a circumference direction, wherein a tooth interstice is disposed between two teeth, in each instance, and each tooth has a head region and a flank region, in each instance, between head region and a foot region disposed in the tooth interstice, wherein the tooth interstice has a tooth gap width in the flank region; wherein the gear-tooth system has at least a first region and subsequently a second region along an axial direction parallel to the first axis of rotation; wherein the first region has a first tooth gap width and the second region has a second tooth gap width, which is less in comparison.

A novel hollow shaft manufacturing method includes the steps of hollow cold-rolling of seamless steel pipe, cutting, annealing and surface treatment, forming by forging, precision machining, and heat treatment. The present invention uses a new process instead of the traditional process. The forging process using high-strength cold-rolled seamless steel pipes has fewer steps than using bar stock: saving three forging passes, one annealing pass and one surface treatment pass, hence saving about ½ in time and cost, shortening the cycle, reducing costs, reducing energy consumption and reducing the three wastes, increasing the stock utilization rate to about 68%, and reducing the inter-process cost calculated by weight. For the same products, using this process can shorten the production cycle.

A method of manufacturing a torsion bar 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.

Provided are a hollow drive shaft using an upsetting method and a method of manufacturing the same, in which hot forging and upsetting processes are applied to both ends of a workpiece so that an outer diameter at both ends of the workpiece is greater than an outer diameter of a middle part of the workpiece, thereby reducing a weight of the drive shaft and enabling the drive shaft to transmit higher driving power. According to the present invention, the upsetting process is applied during the hot forging process to manufacture the hollow drive shaft, portions to be substantially processed are limited to portions at both ends of the workpiece, and the number of upsetting processes is limited to a minimum number (2 or the like), such that initial investment costs and manufacturing costs are low because the number of processes is small.

A method for producing a hollow shaft from a tubular preform by pressure rolling shapes each end of the preform using at least one forming roller. A tubular preform with a round or polygonal cross-section is used, and the preform is held on a workpiece holder in the central tube region during the entire production process until the hollow shaft is completed.

A shaft for a steering device has a first portion, a second portion, and a third portion that is a shaft integrated with the first portion and the second portion and couples the first portion and the second portion in a first direction. The outer diameter of the third portion is smaller than the length of the second portion in a second direction intersecting with the first direction, and is constant across a direction extending along the first direction. The hardness of the third portion is greater than the hardness of the second portion, and is constant across the direction extending along the first direction.