A method and apparatus for processing fuselage sections. A first fuselage section is held in a cradle system. A current shape of the first fuselage section in the cradle system is measured. Forces to change the current shape of the first fuselage section to a desired shape for connecting the first fuselage section to a second fuselage section are identified. The forces identified are applied using a system to change the current shape of the first fuselage section towards the desired shape.

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 rolling mill includes three or more rolling rolls aligned along a circumferential direction and arranged so each rotary shaft is skewed with respect to a pass line of a material to be rolled, wherein the material to be rolled made of a pipe or bar material passes between the rolling rolls while being rotated to undergo diameter reducing rolling. At least one rolling roll selected from the three or more rolling rolls is smaller in roll diameter than at least one other rolling roll. When at least one rolling roll having a relatively maximum roll diameter defined as a maximum diameter rolling roll and at least one rolling roll smaller in roll diameter than the maximum is defined as a small diameter rolling roll, the small diameter rolling roll has a roll diameter equal to or less than 90% of the roll diameter of the maximum diameter rolling roll.

A rolling mill includes three or more rolling rolls aligned along a circumferential direction and arranged so each rotary shaft is skewed with respect to a pass line of a material to be rolled, wherein the material to be rolled made of a pipe or bar material passes between the rolling rolls while being rotated to undergo diameter reducing rolling. At least one rolling roll selected from the three or more rolling rolls is smaller in roll diameter than at least one other rolling roll. When at least one rolling roll having a relatively maximum roll diameter defined as a maximum diameter rolling roll and at least one rolling roll smaller in roll diameter than the maximum is defined as a small diameter rolling roll, the small diameter rolling roll has a roll diameter equal to or less than 90% of the roll diameter of the maximum diameter rolling roll.

A cross-rolling unit and a method for setting the roll pass of a cross-rolling unit, having at least two rolls and a roll housing, in which at least one of the rolls is mounted such that its position can be adjusted in order to change the roll pass, allow the roll pass to be adjusted by means of a roll-positioning apparatus even during rolling, which roll-positioning apparatus is characterized by a housing-connected part and a roller-mill-connected part, which can be moved relative to the housing-connected part during rolling, which parts can be repositioned relative to each other, and/or which roll-positioning apparatus characterized by a drive which is dimensioned in such a way that rolling forces can be applied.

A cross-rolling unit and a method for setting the roll pass of a cross-rolling unit, having at least two rolls and a roll housing, in which at least one of the rolls is mounted such that its position can be adjusted in order to change the roll pass, allow the roll pass to be adjusted by means of a roll-positioning apparatus even during rolling, which roll-positioning apparatus is characterized by a housing-connected part and a roller-mill-connected part, which can be moved relative to the housing-connected part during rolling, which parts can be repositioned relative to each other, and/or which roll-positioning apparatus characterized by a drive which is dimensioned in such a way that rolling forces can be applied.