The present invention is directed to an axial thread rolling process that utilizes a thread rolling head that includes a clutch, that prevents full disengagement of the clutch during thread rolling, and that reverses the direction of rotation used for thread rolling to escape a threaded workpiece from the thread rolling head.

Provided is a screw shaft in which shape accuracy of a male threaded portion is sufficiently secured. A screw shaft includes a large-diameter shaft portion, medium-diameter shaft portions and small-diameter shaft portions. The large-diameter shaft portion has a male threaded portion along its entire axial length on its outer peripheral surface. The medium-diameter shaft portions are arranged axially adjacent to the large-diameter shaft portion and have an outer diameter smaller than an outer diameter of the large-diameter shaft portion. The small-diameter shaft portions are axially arranged adjacent to the medium-diameter shaft portions on sides opposite to the large-diameter shaft portion, have an outer diameter smaller than the outer diameter of each of the medium-diameter shaft portions, and do not have rolling traces having a helical shape on their outer peripheral surfaces.

Provided is a screw shaft in which shape accuracy of a male threaded portion is sufficiently secured. A screw shaft includes a large-diameter shaft portion, medium-diameter shaft portions and small-diameter shaft portions. The large-diameter shaft portion has a male threaded portion along its entire axial length on its outer peripheral surface. The medium-diameter shaft portions are arranged axially adjacent to the large-diameter shaft portion and have an outer diameter smaller than an outer diameter of the large-diameter shaft portion. The small-diameter shaft portions are axially arranged adjacent to the medium-diameter shaft portions on sides opposite to the large-diameter shaft portion, have an outer diameter smaller than the outer diameter of each of the medium-diameter shaft portions, and do not have rolling traces having a helical shape on their outer peripheral surfaces.

A forming machine that produces formed parts of a complex design from straight workpieces from wire or tube includes a computerized numerical control unit; a plurality of workstations including a loading station, a first machining station downstream of the loading station, and at least one second machining station downstream of the first machining station, wherein at least two of the machining stations are forming stations; and a transport system that transports successive workpieces from the loading station to downstream workstations while under control by the control unit.

Provided is a method for performing an external pipe thread process on a hollow blank by at least twice rolling, wherein amount of rolling wheels in a rolling wheel set, used in any two back-to-back rolling processes in a processing sequence, are different in parity. Further provided are various roll-processing modules and corresponding rolling apparatuses, achieving the above processing method and having a simple structure, portability and practicality. A hollow blank is not liable to deform when performing an external pipe thread rolling process thereon, thereby improving a processing yield.

Provided is a method for performing an external pipe thread process on a hollow blank by at least twice rolling, wherein amount of rolling wheels in a rolling wheel set, used in any two back-to-back rolling processes in a processing sequence, are different in parity. Further provided are various roll-processing modules and corresponding rolling apparatuses, achieving the above processing method and having a simple structure, portability and practicality. A hollow blank is not liable to deform when performing an external pipe thread rolling process thereon, thereby improving a processing yield.

The invention relates to a thread-forming screw (10) comprising a base body (12, 20) which comprises a drive and a screw shank, the screw shank carrying a thread (13) having a channeling region (14) and a carrying region, the base body (12, 20) consisting of a base material. The invention is characterized in that the thread (13) is formed from a coating material (18) different from the base material, at least in the channeling region (14), which is applied to the base material by deposition welding.

A fastener with a body with a shank, a head adjacent one end of and integral with the shank, and a shoulder adjacent the head, and a separate washer with a through hole received on the shank, bearing on the shoulder and securely fastened to the shank. The body and washer may have an interference fit. The body may be made and the washer attached by cold forming the body with a ring bearing on the washer.

A fastener with a body with a shank, a head adjacent one end of and integral with the shank, and a shoulder adjacent the head, and a separate washer with a through hole received on the shank, bearing on the shoulder and securely fastened to the shank. The body and washer may have an interference fit. The body may be made and the washer attached by cold forming the body with a ring bearing on the washer.

The invention relates to a thread-forming screw (10) comprising a base body (12, 20) which comprises a drive and a screw shank, the screw shank carrying a thread (13) having a channeling region (14) and a carrying region, the base body (12, 20) consisting of a base material. The invention is characterized in that the thread (13) is formed from a coating material (18) different from the base material, at least in the channeling region (14), which is applied to the base material by deposition welding.