The invention relates to a method for producing seamless steel tubes in a rolling mill train with one or more consecutively positioned longitudinal or cross-rolling units and an inside tool which is used as mandrel bar or piercing plug during the rolling process. The aim is to provide a method to reduce the eccentricity of the rolling stock considerably. To achieve this, the longitudinal axis of the inside tool is forced by means of an apparatus to a movement in a distance to the longitudinal axis of the rolling stock. Simultaneously the rotation of the tool around its axis is kept, driven by the rolling stock during rolling.

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 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 punch sleeve utilized in forming metallic containers, including food and beverage containers, is provided. The punch sleeve comprises two or more different surface textures. In one embodiment, the outer surface of the punch sleeve comprises three regions and each region has a different surface texture. Additionally, a method of texturing two or more different surface textures on an exterior surface of a punch sleeve used in a metallic container manufacturing process is provided. An apparatus for providing two or more surface textures on a punch sleeve used in a metal container manufacturing process is also provided.

A punch sleeve utilized in forming metallic containers, including food and beverage containers, is provided. The punch sleeve comprises two or more different surface textures. In one embodiment, the outer surface of the punch sleeve comprises three regions and each region has a different surface texture. Additionally, a method of texturing two or more different surface textures on an exterior surface of a punch sleeve used in a metallic container manufacturing process is provided. An apparatus for providing two or more surface textures on a punch sleeve used in a metal container manufacturing process is also provided.

A method for manufacturing a strip having a variable thickness along its length, comprising the steps: an initial strip of constant thickness is provided; homogeneous cold rolling of the initial strip along its length in order to obtain an intermediate strip of constant thickness along the rolling direction; flexible cold rolling of the intermediate strip along its length in order to obtain a variable thickness strip, having, along its length, first areas with a first thickness (e+s) and second areas with a second thickness (e), less than the first thickness (e+s), continuous annealing of the strip.

The plastic deformation ratio generated, after an optional intermediate recrystallization annealing, by the homogeneous cold rolling and the flexible cold rolling steps in the first areas is greater than or equal to 30%.

A method for manufacturing a strip having a variable thickness along its length, comprising the steps: an initial strip of constant thickness is provided; homogeneous cold rolling of the initial strip along its length in order to obtain an intermediate strip of constant thickness along the rolling direction; flexible cold rolling of the intermediate strip along its length in order to obtain a variable thickness strip, having, along its length, first areas with a first thickness (e+s) and second areas with a second thickness (e), less than the first thickness (e+s), continuous annealing of the strip.

The plastic deformation ratio generated, after an optional intermediate recrystallization annealing, by the homogeneous cold rolling and the flexible cold rolling steps in the first areas is greater than or equal to 30%.

A punch sleeve utilized in forming metallic containers, including food and beverage containers, is provided. The punch sleeve comprises two or more different surface textures. In one embodiment, the outer surface of the punch sleeve comprises three regions and each region has a different surface texture. Additionally, a method of texturing two or more different surface textures on an exterior surface of a punch sleeve used in a metallic container manufacturing process is provided. An apparatus for providing two or more surface textures on a punch sleeve used in a metal container manufacturing process is also provided.