Abstract: A method for producing a twist drill has the following steps. A blank is shaped to form a semi-finished product. The semi-finished product is formed from a core, coaxial with the drill axis, having a radius and a number of webs, arranged on the core, having a height. The semi-finished product has a constant cross section along the drill axis. The webs have a first portion which adjoins the core and in which a width of the web remains constant or decreases in the circumferential direction with increasing radial distance from the drill axis. The webs have a second portion which adjoins the first portion and in which the width of the web increases in the circumferential direction with increasing radial distance from the drill axis. The webs of the semi-finished product are shaped into helical segments using a plurality of rolling tools that annularly enclose the semi-finished product and roll on the webs along the drill axis. The rolling tools have teeth that are inclined with respect to the drill axis.

Abstract: The twist drill (1) has a drilling head (3), a continuous two-flute, three-flute to six-flute helix (4) and an insertion end (5) that are arranged consecutively on a drill axis (2). The helix (4) has a radial outer dimension (18) that varies periodically two, three to six times per revolution around the drill axis (2). The invention also relates to a production method for such a drill.

Abstract: A method for producing a twist drill has the following steps. A blank is shaped to form a semi-finished product. The semi-finished product is formed from a core, coaxial with the drill axis, having a radius and a number of webs, arranged on the core, having a height. The semi-finished product has a constant cross section along the drill axis. The webs have a first portion which adjoins the core and in which a width of the web remains constant or decreases in the circumferential direction with increasing radial distance from the drill axis. The webs have a second portion which adjoins the first portion and in which the width of the web increases in the circumferential direction with increasing radial distance from the drill axis. The webs of the semi-finished product are shaped into helical segments using a plurality of rolling tools that annularly enclose the semi-finished product and roll on the webs along the drill axis. The rolling tools have teeth that are inclined with respect to the drill axis.

Abstract: A rolling die for forming a screw thread on a screw blank is disclosed. The rolling die has a plurality of grooves, where the grooves each have two flanks as seen in cross-section. At least a portion of each of the grooves has a forming area in which the size of a profile angle enclosed by the flanks decreases continuously along the grooves.

Abstract: The twist drill (1) has a drilling head (3), a continuous two-flute, three-flute to six-flute helix (4) and an insertion end (5) that are arranged consecutively on a drill axis (2). The helix (4) has a radial outer dimension (18) that varies periodically two, three to six times per revolution around the drill axis (2). The invention also relates to a production method for such a drill.

Abstract: A concrete screw is disclosed. The concrete screw includes a shank and a thread disposed on the shank with a thread helix and a thread root. A cutting recess is disposed in a tip region of the shank where the cutting recess runs at least in sections within the thread root and without interrupting the thread helix. A rolling die for producing the concrete screw and a method for producing the concrete screw are also disclosed.

Abstract: A method for producing a concrete screw is disclosed. The method includes providing a wire piece as a workpiece, forming a thread helix on a lateral surface of the workpiece, and providing a depression in the lateral surface of the workpiece by a forming process.

Abstract: A method for producing a concrete screw is disclosed. The lateral surface of the shaft includes, on the end of the shaft, at least one cut-out recess. A piece of rod is provided as a workpiece, at least one threaded coil is formed on the lateral surface in a thread rolling process in which two profiled rolling tools act on the workpiece, and at least one recess is formed in the lateral surface on an end area of the workpiece. The recess, when seen in the cross-section of the workpiece, is diametrically opposite an area of the workpiece free of recesses such that initially the recess is formed in the lateral surface and subsequently, the threaded coil is formed on the lateral surface of the workpiece, and at least one of the rolling tools also acts upon the end area with the recess during the thread rolling process.

Abstract: In the case of a screw having at least one thread (26) that is formed by a rolling process, especially a flat-die rolling process, whereby the thread (26) consists of two ridges of material (28a, 28b) which are shaped from a blank (12) by means of cold-forming during the rolling process in such a way that the thread has a closing crease (32) where the ridges of material (28a, 28b) meet each other, it is provided that the closing crease (32) is situated in the area of a flank (30a, 30b) of the thread (26).

Abstract: A method for manufacturing a thread-forming screw having a shank and a thread formed in one piece with the shank and region-wise circumferentially arranged on the shank, is disclosed. After the formation of the thread on the shank, a plurality of recesses is subsequently stamped into the thread. Then, a plurality of compact cutting elements is welded into the recesses in the thread, where the cutting elements are made of a hard material and have a hardness greater than the hardness of the thread. Additionally, a stamping device for carrying out the method is also disclosed.

Abstract: A self-tapping screw is disclosed. The screw includes a shaft which has a first end and an opposing second end with a load-engaging structure, and a thread that extends at least in sections over the length of the shaft. Several wear indicators are provided on the thread. Identifiers are provided on the screw for identifying the wear indicators.

Abstract: In the case of a screw having at least one thread (26) that is formed by a rolling process, especially a flat-die rolling process, whereby the thread (26) consists of two ridges of material (28a, 28b) which are shaped from a blank (12) by means of cold-forming during the rolling process in such a way that the thread has a closing crease (32) where the ridges of material (28a, 28b) meet each other, it is provided that the closing crease (32) is situated in the area of a flank (30a, 30b) of the thread (26).

Abstract: A rolling die for forming a screw thread on a screw blank is disclosed. The rolling die has a plurality of grooves, where the grooves each have two flanks as seen in cross-section. At least a portion of each of the grooves has a forming area in which the size of a profile angle enclosed by the flanks decreases continuously along the grooves.

Abstract: A self-tapping screw is disclosed. The screw includes a shaft which has a first end and an opposing second end with a load-engaging structure, and a thread that extends at least in sections over the length of the shaft. Several wear indicators are provided on the thread. Identifiers are provided on the screw for identifying the wear indicators.

Abstract: A method for manufacturing a thread-forming screw having a shank and a thread formed in one piece with the shank and region-wise circumferentially arranged on the shank, is disclosed. After the formation of the thread on the shank, a plurality of recesses is subsequently stamped into the thread. Then, a plurality of compact cutting elements is welded into the recesses in the thread, where the cutting elements are made of a hard material and have a hardness greater than the hardness of the thread. Additionally, a stamping device for carrying out the method is also disclosed.