Electric resistance welded steel pipes or steel tubes with a tensile property TS of not less than 434 MPa which have electric resistance welded parts exhibiting both excellent HIC resistance and excellent low-temperature toughness, and methods for manufacturing such steel pipes or steel tubes.

Electric resistance welded steel pipes or steel tubes with a tensile property TS of not less than 434 MPa which have electric resistance welded parts exhibiting both excellent HIC resistance and excellent low-temperature toughness, and methods for manufacturing such steel pipes or steel tubes.

The descaling device (100) of the interior of a tube (1) comprises a supporting structure (9), a conveyor (2) for conveying the tube (1) with an inclinable stretch to arrange the tube in an inclined position by an angle with respect to the horizontal plane, a lance (3) with nozzles (4) to spray a fluid inside the tube (1) to carry out the operation of descaling the inner surface. The lance (3) is fixed to guides (7) above the conveyor (2) in an inclined position with respect to the horizontal plane, and may axially slide within the tube (1) during the descaling operation by spraying water into the tube.

The present invention relates to a plant 10 for rolling a seamless tube. The plant comprises a rotary piercer 20 which is designed to pierce a billet 11 pressed against a plug 22 mounted on a rod so as to obtain a pierced blank 12. The rod is connected to a thrust block 26 designed to oppose the axial thrust which is produced on the rod during piercing. The plant also comprises a longitudinal mill 30 which is designed to roll the pierced blank 12 on a mandrel 32 so as to obtain a semi-finished tube 13. The mandrel is connected to a retaining block 34 designed to impart to the mandrel a predetermined speed during rolling. In the plant according to the invention the thrust block 26 and the retaining block 34 are formed by a single thrust/retaining block 36.

The invention also relates to a method for rolling a seamless tube.

A device for rolling of pipe blanks has a planetary cross-rolling mill, an advancing bed, a pipe blank feed, a pipe blank advancing unit that pushes the pipe blanks through the planetary cross-rolling mill, proceeding from the advancing bed, the unit having at least one advancing apparatus, and having a mandrel rod and a mandrel rod holder. The pipe blank feed has an axial pipe blank conveying unit that conveys a pipe blank axially into a readiness position, which is provided axially behind the mandrel rod holder. The advancing apparatus is disposed between the planetary cross-rolling mill and the mandrel rod holder, and has a slide.

A device for rolling of pipe blanks has a planetary cross-rolling mill, an advancing bed, a pipe blank feed, a pipe blank advancing unit that pushes the pipe blanks through the planetary cross-rolling mill, proceeding from the advancing bed, the unit having at least one advancing apparatus, and having a mandrel rod and a mandrel rod holder. The pipe blank feed has an axial pipe blank conveying unit that conveys a pipe blank axially into a readiness position, which is provided axially behind the mandrel rod holder. The advancing apparatus is disposed between the planetary cross-rolling mill and the mandrel rod holder, and has a slide.

An apparatus, method and composition for long length tubing includes continuous production of long length seamless aluminum tubing suitable for use as coiled tubing in hydrocarbon wells. A 2XXX aluminum alloy may be used in combination with a continuous casting/extrusion apparatus using aluminum from a melt. Other metals may be used, as well as continuously cast rod from a casting wheel and belt or conform extruder, which is processed to form a hollow and then sized by drawing.

A method for forming an end part of a tube, such as a hollow shaft for use as a vehicle axle, is described. A rolling body having a rolling surface with an inwardly-curved contour rotates around a longitudinal axis with a first rotational speed and a second rotational speed. The rolling body and the tube rotate in the same direction. The longitudinal axis of the rolling body is arranged eccentrically to a longitudinal axis of the tube by a predetermined normal distance. The rolling body and the tube are brought into contact such that the rolling surface contacts the end part of the tube at a contact surface situated on an inner tube wall. The rolling body transfers a force to the inner tube wall by a relative movement between the rolling body and the tube such that the end part of the tube is formed radially outward.

A method for forming an end part of a tube, such as a hollow shaft for use as a vehicle axle, is described. A rolling body having a rolling surface with an inwardly-curved contour rotates around a longitudinal axis with a first rotational speed and a second rotational speed. The rolling body and the tube rotate in the same direction. The longitudinal axis of the rolling body is arranged eccentrically to a longitudinal axis of the tube by a predetermined normal distance. The rolling body and the tube are brought into contact such that the rolling surface contacts the end part of the tube at a contact surface situated on an inner tube wall. The rolling body transfers a force to the inner tube wall by a relative movement between the rolling body and the tube such that the end part of the tube is formed radially outward.

A fastener includes a screw head and a screw shank. The screw head has a top surface and an inner surrounding surface. The inner surrounding surface has six curved portions and six driven portions disposed in an alternating arrangement. Each of the driven portions has a curved section connected to one of two adjacent curved portions and having a direction of curvature opposite to that of the one of the two adjacent curved portions, a straight section extending along a tangent line of an end of the curved section, and an extension section connected between the straight section and the other one of the two adjacent curved portions.