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 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.

Composite tube assemblies and thin-walled tubing are disclosed. In embodiments, the composite tube assemblies include a functional tube and a sacrificial tube disposed within or around the functional tube. The sacrificial tube may be removed by exposure to a corrosive media, without substantially affecting the functional tube. Methods of forming composite tube assemblies and thin-walled tubing are also described.

There is provided a method of manufacturing a variable wall thickness steel pipe with a hollow tubular raw pipe. The method of manufacturing a variable wall thickness steel pipe includes locking the raw pipe in a die by thrusting a plug into the raw pipe from an one end side, so as to expand an outer shape on the one end side in a state, where the raw pipe is disposed inside the die and movement of the raw pipe in a longitudinal direction is restricted; and performing ironing in which an inner shape of the raw pipe is expanded while the outer shape is maintained so that a thin portion is formed by further thrusting the plug toward the other end side of the raw pipe while the locked state of the raw pipe is maintained, whereas the restriction on the raw pipe is relaxed.

There is provided a method of manufacturing a variable wall thickness steel pipe with a hollow tubular raw pipe. The method of manufacturing a variable wall thickness steel pipe includes locking the raw pipe in a die by thrusting a plug into the raw pipe from an one end side, so as to expand an outer shape on the one end side in a state, where the raw pipe is disposed inside the die and movement of the raw pipe in a longitudinal direction is restricted; and performing ironing in which an inner shape of the raw pipe is expanded while the outer shape is maintained so that a thin portion is formed by further thrusting the plug toward the other end side of the raw pipe while the locked state of the raw pipe is maintained, whereas the restriction on the raw pipe is relaxed.

A lumen stent preform is provided using a plasma nitriding technology, a preparation method thereof, a method for preparing a lumen stent by using the preform, and a lumen stent obtained according to the method. The preform is manufactured by using pure iron or an iron alloy containing no strong nitrogen compound, has a hardness of 160-250HV0.05/10, and has a microstructure that is a deformed structure having a grain size scale greater than or equal to 9 or a deformed structure after cold machining. Alternatively, the preform is an iron alloy containing a strong nitrogen compound, and has a microstructure that is a deformed structure having a grain size scale greater than or equal to 9 or a deformed structure after cold machining. The lumen stem preform meets the requirements of a conventional stent for radial strength and plasticity, so that plasma nitriding is applicable to commercial preparation of a lumen stent.

To provide methods, apparatuses and drawing mandrels in which the shaping process can be monitored as closely as possible, a drawing machine and a drawing method manufactures or processes tubes, which extend in the direction of longitudinal extent, from a semi-manufactured product, wherein the drawing machine includes a drawing device for drawing a hollow workpiece formed by the tube and the semi-manufactured product in the direction of longitudinal extent, a drawing ring and a drawing mandrel and acts on the workpiece in a shaping manner via the drawing mandrel and the drawing ring while the workpiece is drawn by the drawing device around the drawing mandrel and through the drawing ring. A sensor is located on the drawing mandrel, or physical properties are measured in the interior of the workpiece and/or on the drawing mandrel using a sensor on the drawing mandrel.

To provide methods, apparatuses and drawing mandrels in which the shaping process can be monitored as closely as possible, a drawing machine and a drawing method manufactures or processes tubes, which extend in the direction of longitudinal extent, from a semi-manufactured product, wherein the drawing machine includes a drawing device for drawing a hollow workpiece formed by the tube and the semi-manufactured product in the direction of longitudinal extent, a drawing ring and a drawing mandrel and acts on the workpiece in a shaping manner via the drawing mandrel and the drawing ring while the workpiece is drawn by the drawing device around the drawing mandrel and through the drawing ring. A sensor is located on the drawing mandrel, or physical properties are measured in the interior of the workpiece and/or on the drawing mandrel using a sensor on the drawing mandrel.

A multi-walled tube that is useful as an analytical column in which chemical mixtures can be separated into their individual components is described. In order to be acceptable as an analytical column, the inner surface of the multi-walled tube must support effective separation, but not react chemically with or contaminate the solvent or the analyte (sample to be separated). Grade 316 stainless steel is typically preferred for this purpose. Moreover, the inner diameter (ID) surface of the multi-walled column is preferably very smooth (less than 10 micro inch Ra) with no interruptions in the surface such as scratches, pits, or asperities. However, since the column is designed to be attached to chromatographic equipment using standard size connection features, the size of standard fittings define the outer diameter (OD) of the column.

A lumen stent preform is provided using a plasma nitriding technology, a preparation method thereof, a method for preparing a lumen stent by using the preform, and a lumen stent obtained according to the method. The preform is manufactured by using pure iron or an iron alloy containing no strong nitrogen compound, has a hardness of 160-250HV0.05/10, and has a microstructure that is a deformed structure having a grain size scale greater than or equal to 9 or a deformed structure after cold machining. Alternatively, the preform is an iron alloy containing a strong nitrogen compound, and has a microstructure that is a deformed structure having a grain size scale greater than or equal to 9 or a deformed structure after cold machining. The lumen stent preform meets the requirements of a conventional stent for radial strength and plasticity, so that plasma nitriding is applicable to commercial preparation of a lumen stent.