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.

An apparatus for reducing the cross-section of a tubular hollow body with a hollow body wall has a shaping die on the outer side of the hollow body, a mandrel in the interior of the hollow body, and a shaping drive with a mandrel drive and a die drive. The shaping die is movable by the die drive to reduce a cross-section of the hollow body with an axial movement of the die. The mandrel is movable via the mandrel drive along the hollow body axis through the die opening in the shaping die. The hollow body wall is subjected to a tensile stress by the mandrel and is drawn in the direction of the axial movement of the mandrel through the die opening. The mandrel drive and the die drive are controlled so that the axial mandrel movement and the axial die movement die are superimposed on one another.

Method for manufacturing a tube of metal in which sensors are attached to tubes, which register and signal a damage of the tube. It is detrimental that protection of the sensors at these tubes against environmental influences is complex. In contrast, it is an object of the present disclosure to provide a method for manufacturing a tube, in which the signal line can be protectively mounted. To solve this object, a method for manufacturing a tube of metal is suggested with an outer tube and an inner tube, wherein a groove is drawn in an inner surface of the outer tube or in an outer surface of the inner tube and subsequently the inner tube and the outer tube are drawn together through a drawing die, wherein the inner dimension of the outer tube is reduced such that after the drawing the outer tube is force-fitted onto the inner tube.

Method for manufacturing a tube of metal in which sensors are attached to tubes, which register and signal a damage of the tube. It is detrimental that protection of the sensors at these tubes against environmental influences is complex. In contrast, it is an object of the present disclosure to provide a method for manufacturing a tube, in which the signal line can be protectively mounted. To solve this object, a method for manufacturing a tube of metal is suggested with an outer tube and an inner tube, wherein a groove is drawn in an inner surface of the outer tube or in an outer surface of the inner tube and subsequently the inner tube and the outer tube are drawn together through a drawing die, wherein the inner dimension of the outer tube is reduced such that after the drawing the outer tube is force-fitted onto the inner tube.

A support may include a hollow metallic tube extending over an axis and may include two opposing ends. The tube may include a plurality of sections disposed along the axis. A first section may be disposed at an end of the tube and include a first inner diameter, a first outer diameter, and a first wall thickness. A second section may be separated from the first section via a first transition zone. The second section may include a second inner diameter, a second outer diameter, and a second wall thickness. A third section may be disposed remote from the first section and be separated from the second section via a second transition zone. The third section may have a third inner diameter, a third outer diameter, and a third wall thickness. The wall thickness, inner diameter and outer diameter may vary along the tube between the plurality of sections.

A support may include a hollow metallic tube extending over an axis and may include two opposing ends. The tube may include a plurality of sections disposed along the axis. A first section may be disposed at an end of the tube and include a first inner diameter, a first outer diameter, and a first wall thickness. A second section may be separated from the first section via a first transition zone. The second section may include a second inner diameter, a second outer diameter, and a second wall thickness. A third section may be disposed remote from the first section and be separated from the second section via a second transition zone. The third section may have a third inner diameter, a third outer diameter, and a third wall thickness. The wall thickness, inner diameter and outer diameter may vary along the tube between the plurality of sections.

An apparatus for preparing a tube end for rod drawing with a floating mandrel has a releasable holder for the tube end centered on an axis, a frustoconical and spreadable floating mandrel, and a device for inserting the mandrel into the tube end and spreading the mandrel to flare the tube end. The apparatus further has a feed mechanism for inserting the floating mandrel into the tube end and/or a deforming device for making at least one indentation in the tube for holding the floating mandrel.

An apparatus for preparing a tube end for rod drawing with a floating mandrel has a releasable holder for the tube end centered on an axis, a frustoconical and spreadable floating mandrel, and a device for inserting the mandrel into the tube end and spreading the mandrel to flare the tube end. The apparatus further has a feed mechanism for inserting the floating mandrel into the tube end and/or a deforming device for making at least one indentation in the tube for holding the floating mandrel.

Through a tube expanding processing simulation, a workpiece shape in a state where a tip of a workpiece 10 has advanced by 1.0 m or more after passing through a shoulder portion 3 of a tool 1 is evaluated. A hollow piece shape and a tool shape such that the external diameter is within 1% of the target, the thickness is within 7.5% of the target, and the internal gap between the hollow piece and the tool is 1.0 mm or less are obtained by repeated calculation, and thereby actual tube expanding manufacturing conditions are determined.

Through a tube expanding processing simulation, a workpiece shape in a state where a tip of a workpiece 10 has advanced by 1.0 m or more after passing through a shoulder portion 3 of a tool 1 is evaluated. A hollow piece shape and a tool shape such that the external diameter is within 1% of the target, the thickness is within 7.5% of the target, and the internal gap between the hollow piece and the tool is 1.0 mm or less are obtained by repeated calculation, and thereby actual tube expanding manufacturing conditions are determined.