An electric resistance welded steel pipe having excellent formability and torsional fatigue resistance and a method for manufacturing the same. The electric resistance welded steel pipe includes a seam region and a base metal region, the seam region having a range of ±10 degrees in a pipe circumferential direction with respect to an electric resistance welded seam formed in a pipe longitudinal direction, the base metal region being a region other than the seam region. The electric resistance welded steel pipe has an r-value in the pipe longitudinal direction of 1.0 or greater, H (mm) and W (mm) satisfy a specified formula, and Ts.sub.(MAX) (mm) and Tb.sub.(Ave) (mm) satisfy a specified formula.

An electric resistance welded steel pipe having excellent formability and torsional fatigue resistance and a method for manufacturing the same. The electric resistance welded steel pipe includes a seam region and a base metal region, the seam region having a range of ±10 degrees in a pipe circumferential direction with respect to an electric resistance welded seam formed in a pipe longitudinal direction, the base metal region being a region other than the seam region. The electric resistance welded steel pipe has an r-value in the pipe longitudinal direction of 1.0 or greater, H (mm) and W (mm) satisfy a specified formula, and Ts.sub.(MAX) (mm) and Tb.sub.(Ave) (mm) satisfy a specified formula.

In a method for manufacturing a metal pipe from a metal plate using a forming tool, the position of the tool is optimized simply and correctly by incorporating individuality of the raw material plate into setting of the tool position.

As a preparatory stage, a forming process is analyzed by simulation for each plate. Based on result of the analysis, correlation between a deformed shape value of a raw pipe and tool position information is acquired. Then, the forming process for each plate is stored as correlation between the deformed shape value of the raw pipe and the tool position information. During pipe manufacturing, a deformed shape value of the raw pipe is measured actually while a plate is passed. On the basis of the actually measured deformed shape value, a forming process for the raw pipe is expected and assumed (by using the correlation). Tool position information necessary for implementing the expected and assumed forming process is retrieved from the stored correlation. The retrieved tool position information is realized at a stand array.

A crimping machine including a first shaft having a first crimping portion and a bead wheel and a second shaft having a tapered portion disposed opposite the bead wheel of the first shaft. The first and second shafts are configured to grip a pipe blank having a transverse channel including a first angle. The first and second shafts are further configured to roll the pipe blank forward while crimping a portion of the pipe blank with the first and second crimping portions and applying pressure on the transverse channel of the pipe blank. The crimping machine further has having a tapered portion disposed opposite at least a portion of the crimping portion and the bead wheel of the first shaft. The bead wheel is configured to push upon the forming shaft to bend the first angle of the transverse channel formed in the pipe blank to a second angle.

A forming unit for a profiling machine line, comprising: a plurality of lower rollers (11,12,13) shaped with outer surfaces that envelop, on at least a transversal section plane, a lower curve (P1); a plurality of upper rollers (21,22,23,24,25) profiled with outer surfaces that envelop, on the transversal section plane, an upper curve (P2) substantially parallel to the lower curve (P1).

A roll forming machine for continuously forming a sheet into a joint section of a tube may include a plurality of roller stations arranged longitudinally on a frame and configured to bend the sheet to form the tube, and a carriage slidably secured to the frame. A pleat die assembly may be mounted on the carriage and can be configured to repeatedly engage the tube to form a series of pleats thereby bending the tube to form the joint section. A crimp die assembly may be mounted on the carriage and can be configured to engage the tube to crimp an end of the joint section and sever the end of the joint section from the tube. The carriage may be configured to be selectively moved relative to the frame while the tube is engaged with at least one of the crimp die assembly and the pleat die assembly.

Provided is a method for manufacturing a cylindrical member which includes end bending of respective end portions of a plate material in a longitudinal direction, primary grooving of respective end surfaces of the plate material subjected to end bending, bending of the plate material to a ring shape, secondary grooving of respective end surfaces of the plate material subjected to bending in a ring shape, and joining of respective end surfaces of the plate material. Therefore, it is possible to manufacture a high-quality cylindrical member.

A roller cage for a profiling line, comprising: a support frame (F1) that entirely delimits a non-operating area (A1) which is external to the line; at least a motor (11) provided with a spindle (12) protruding externally of the non-operating area (A1); at least a shaped roller (13, mounted directly on the spindle (12) and arranged inside an operating area (B) of the line.

A roller cage for a profiling line, comprising: a support frame (F1) that entirely delimits a non-operating area (A1) which is external to the line; at least a motor (11) provided with a spindle (12) protruding externally of the non-operating area (A1); at least a shaped roller (13, mounted directly on the spindle (12) and arranged inside an operating area (B) of the line.

A roll forming machine for continuously forming a sheet into a joint section of a tube may include a plurality of roller stations arranged longitudinally on a frame and configured to bend the sheet to form the tube, and a carriage slidably secured to the frame. A pleat die assembly may be mounted on the carriage and can be configured to repeatedly engage the tube to form a series of pleats thereby bending the tube to form the joint section. A crimp die assembly may be mounted on the carriage and can be configured to engage the tube to crimp an end of the joint section and sever the end of the joint section from the tube. The carriage may be configured to be selectively moved relative to the frame while the tube is engaged with at least one of the crimp die assembly and the pleat die assembly.