A manufacturing method of a seamless metal pipe includes: preparing a plurality of mandrel bars in which lengths of work portions which come into contact with a hollow shell during elongating are different from one another; selecting a mandrel bar including a work portion having a length corresponding to the number of stands used in thickness reduction, among the plurality of mandrel bars; inserting the mandrel bar selected in the selecting into the hollow shell; and performing the elongating on the hollow shell into which the mandrel bar is inserted. Moreover, in the elongating, outer diameter reduction is performed by one of a preceding-stage stand group and a succeeding-stage stand group and the thickness reduction is performed by the other of the preceding-stage stand group and the succeeding-stage stand group, or the thickness reduction is performed by both of the preceding-stage stand group and the succeeding-stage stand group.

In order to provide an adjustment of the roll gap under load with high positioning accuracy and regulation accuracy, a cross-rolling unit for adjusting rolls operating under load with, disposed on a force-absorbing roll stand, a mechanical setting unit for a first cross-roll setting and a hydraulic setting unit for a second cross-roll setting, wherein the mechanical setting unit includes two mutually displaceable mechanical subassemblies having a common axis of symmetry and the hydraulic setting unit includes at least two mutually displaceable hydraulic subassemblies having respectively one central axis, has the mechanical setting unit and the hydraulic setting unit disposed in the force-absorbing roll stand as a common subassembly. The axis of symmetry of at least one of the mutually displaceable mechanical subassemblies and the central axes of each of the mutually displaceable hydraulic subassemblies are the same.

In order to provide an adjustment of the roll gap under load with high positioning accuracy and regulation accuracy, a cross-rolling unit for adjusting rolls operating under load with, disposed on a force-absorbing roll stand, a mechanical setting unit for a first cross-roll setting and a hydraulic setting unit for a second cross-roll setting, wherein the mechanical setting unit includes two mutually displaceable mechanical subassemblies having a common axis of symmetry and the hydraulic setting unit includes at least two mutually displaceable hydraulic subassemblies having respectively one central axis, has the mechanical setting unit and the hydraulic setting unit disposed in the force-absorbing roll stand as a common subassembly. The axis of symmetry of at least one of the mutually displaceable mechanical subassemblies and the central axes of each of the mutually displaceable hydraulic subassemblies are the same.

A manufacturing method of a seamless metal pipe includes determining whether a preceding-stage stand group is used in outer diameter reduction or in thickness reduction of a hollow shell; and performing elongating on the hollow shell, into which a mandrel bar is inserted, based on the determination. In addition, in the elongating, when the preceding-stage stand group is used in the outer diameter reduction, the hollow shell is rolled in a state where an inner surface of the hollow shell does not come into contact with the mandrel bar in the preceding-stage stand group, and the hollow shell is rolled in a state where the inner surface of the hollow shell comes into contact with the mandrel bar in the succeeding-stage stand group.

A method and a device for releasing a tube during a rolling process in a three-roll rolling stand in case of an emergency. The roll holder cartridge (3) has a longitudinal open slot (10) at the yoke support of the vertical axis roll so as to remove the roll holder cartridge according to a direction coinciding with the horizontal axis of the yoke support of the vertical axis roll while the support remains anchored to the fixed structure in the stand of the roll mill. In case of routine maintenance, the cartridge (3) is pulled out laterally with the yoke support of the vertical axis roll anchored to the cartridge itself as the other roll supports.

A method and a device for releasing a tube during a rolling process in a three-roll rolling stand in case of an emergency. The roll holder cartridge (3) has a longitudinal open slot (10) at the yoke support of the vertical axis roll so as to remove the roll holder cartridge according to a direction coinciding with the horizontal axis of the yoke support of the vertical axis roll while the support remains anchored to the fixed structure in the stand of the roll mill. In case of routine maintenance, the cartridge (3) is pulled out laterally with the yoke support of the vertical axis roll anchored to the cartridge itself as the other roll supports.

The present application relates to a stand (1) for rolling metal rods, wires, or pipes, along a rolling axis (19). The stand (1) comprises three rollers (20.1, 20.2, 20.3) which are located on one roller shaft in each case and surround the rolling axis (19) in a star-shaped manner, and which together form a caliber (21), a stand housing (10) having an outside (12) which, viewed along the rolling axis (19), comprises at least six side surfaces (14.1, 14.2, 14.3, 14.4, 14.5, 14.6) that are arranged so as to be offset about the rolling axis (19), about a 60 rotation in each case, and two end faces (13, 15) which are opposite one another, wherein the side surfaces (14.1-14.6) form a regular hexagon, at least in an imagine extension, and a roller guide (60) which is attached to one of the end faces (13, 15) of the stand housing (10) and comprises a universal shaft (62), wherein the universal shaft (62) comprises a roller adjustment connector (64) via which a central adjustment of the roller guide (60) is possible and which is attached on the stand housing (10) in one corner (16.1, 16.2, 16.3, 16.4, 16.5, 16.6) of the hexagon.

The present application relates to a stand housing (10) for a stand (1) for rolling metal rods, wires or pipes along a rolling axis (19), which comprises at least four contact surfaces which are arranged on an outside (12) of the stand housing (10) and which, viewed along the rolling axis (19), are in parallel therewith. Of the contact surfaces, two form non-adjacent, mutually parallel contact surfaces, and the two others form adjacent contact surfaces. In this case, the adjacent contact surfaces are at an angle of 120 to one another, and each thereof is at an angle of 120 to one of the parallel contact surfaces. The two parallel contact surfaces and/or the adjacent contact surfaces are designed to receive sliding rails (40.2, 40.3, 40.4, 40.5) for inserting the stand housing (10) into a stand base.

The present application relates to a stand housing (10) for a stand (1) for rolling metal rods, wires or pipes along a rolling axis (19), wherein the stand housing (10) comprises an outside (12) having six side surfaces (14.1-14.6) which, viewed along the rolling axis (19), form edges of a regular hexagon, an inlet side (15), and an outlet side (13). In this case, at least one water feed opening (43.1, 43.2, 43.3) is arranged on three of the side surfaces (14.1, 14.3, 14.5) that are not adjacent in each case, which opening is designed to conduct water through the interior of the stand housing (10) to a water outlet opening (42.1, 42.2, 42.3) in the outlet side (13) or in the inlet side (15).

A stretch reducer and/or calibrating rolling mill for rod-shaped bodies, in particular tubular bodies, in particular hollow bodies, said rolling mill comprising a plurality of rolling stands each comprising a plurality of rolling rollers mutually arranged so as to define a passage for said rod-shaped bodies, wherein said rolling stands are arranged in sequence along a rolling direction so that the respective passages are substantially aligned to define a rolling path substantially parallel to said rolling direction, wherein each of at least two of said rolling stands comprises three rolling rollers.