A thread-rolling flat die for a threaded fastener, includes a thread-rolling surface including at least a bite surface to which a workpiece of the threaded fastener is supplied, a finishing surface formed adjacent to the bite surface, and a roll-off surface formed adjacent to the finishing surface. The bite surface includes at least: a first partial bite surface having an inclination and a second partial bite surface formed continuously from the first partial bite surface and having an inclination. A length L1 along a thread-rolling direction in the first partial bite surface, a length L3 along the thread-rolling direction in the finishing surface, a length L4 along the thread-rolling direction in the roll-off surface, and a diameter of a processed portion of the workpiece of the threaded fastener have a relationship of L1>L3>L4> the diameter of the processed portion.

A wood screw, having a shaft, a screw tip, and thread turns. The thread turns run circumferentially on at least a portion of the shaft, preferably through or into a screw tip. The wood screw includes at least one arc-shaped protrusion between at least two adjoining ones of the thread turns.

A rolled-thread bolt production method includes: forming a steel wire into a workpiece having a prescribed unthreaded-bolt shape; forming a threaded-portion on the workpiece through thread rolling; and performing shot blasting on an entire surface of the workpiece after forming the threaded-portion.

A rolled-thread bolt production method includes: forming a steel wire into a workpiece having a prescribed unthreaded-bolt shape; forming a threaded-portion on the workpiece through thread rolling; and performing shot blasting on an entire surface of the workpiece after forming the threaded-portion.

A method for producing a screw foundation for securing elements in the ground, provides a cylindrical tube as an initial form and a conical front portion tapering to an insertion tip is then molded on to the cylindrical tube using a non-cutting process, the front portion being provided at least in some regions with a thread-like contour for screwing into the ground. An inner contour for a screwing tool is formed integrally in a rear end of the tube by flow forming, and the front portion and the thread-like contour are formed exclusively by flow forming.

A method and a device for producing an outer pipe of a telescope-like support, for reasons of weight and stability, is produced from a standardized zinc-coated steel pipe having a large outer diameter and a small wall thickness. Also included is the telescope-like support and the outer pipe which is contained therein. A pipe portion of the outer pipe is expanded in the method with a punch and subsequently tapered to the original outer diameter again with a ring. A reinforcement of the pipe portion and a calibration of the outer diameter of the pipe portion are thereby achieved. An outer thread can be rolled on the pipe portion.

A method and a device for producing an outer pipe of a telescope-like support, for reasons of weight and stability, is produced from a standardized zinc-coated steel pipe having a large outer diameter and a small wall thickness. Also included is the telescope-like support and the outer pipe which is contained therein. A pipe portion of the outer pipe is expanded in the method with a punch and subsequently tapered to the original outer diameter again with a ring. A reinforcement of the pipe portion and a calibration of the outer diameter of the pipe portion are thereby achieved. An outer thread can be rolled on the pipe portion.

A turning and thread-rolling machine with a pre-compression device includes a fixing base on which the pre-compression device, a fixing mechanism, a guiding base, a processing mechanism assembly, and a control unit are provided, wherein the pre-compression device includes a carrier and at least two cold-rolling heads in order to form by compression a pre-compressed annular groove in a portion of an unprocessed rebar that is adjacent to one end thereof, and, under the control of the control unit, the fixing mechanism clamps the rebar, and the guiding base displaces the processing mechanism assembly to the end of the rebar to perform turning and thread rolling sequentially, thereby processing the end of the rebar into a coupling end. The pre-compressed annular groove facilitates on-site inspection of thread quality and prevents the thread-rolling dies in the processing mechanism assembly from contact with, and hence damage by, the ribs on the rebar.

A turning and thread-rolling machine with a pre-compression device includes a fixing base on which the pre-compression device, a fixing mechanism, a guiding base, a processing mechanism assembly, and a control unit are provided, wherein the pre-compression device includes a carrier and at least two cold-rolling heads in order to form by compression a pre-compressed annular groove in a portion of an unprocessed rebar that is adjacent to one end thereof, and, under the control of the control unit, the fixing mechanism clamps the rebar, and the guiding base displaces the processing mechanism assembly to the end of the rebar to perform turning and thread rolling sequentially, thereby processing the end of the rebar into a coupling end. The pre-compressed annular groove facilitates on-site inspection of thread quality and prevents the thread-rolling dies in the processing mechanism assembly from contact with, and hence damage by, the ribs on the rebar.

A metric self-tapping locking screw comprises a screw head which is connected to a thread locking body by a screw rod. The thread locking body and the self-tapping tip are provided with a screw thread on the surface. The self-tapping tip is arranged at the root of the thread locking body; the screw thread adopts the basic structure of the standard ordinary triangular thread. The flank angle back to the fastened surface is 15-20 and the flank angle of the screw thread facing the fastened surface is 30. The metric self-tapping locking screw in the Invention make the installed parts to be fastened have higher axial clamping force and static loosing moment, which solves the attenuation problem of axial clamping force and static moment of fastened parts.