A screw includes a shank with an outer periphery, a head connected to the shank, and thread convolutions spiraling around the shank in a right-hand direction. The outer periphery defines opposite first and second peripheral envelope surfaces. A cutting slot unit is formed on the shank and arranged on the first peripheral envelope surface. The cutting slot unit includes a first cutting slot with two first edges and a second cutting slot with two second edges. The first edge extends in an extension direction opposite to the right-hand direction. One first edge of the first cutting slot is parallel to one second edge of the second cutting slot. The opposite extension of the cutting slot unit assists the screw in screwing quickly, attains quick removal of chips, and increases the fastening effect by pressing chips downwards.

A self-drilling self-tapping fastener that provides improved performance in both drilling time and pullout force without decreasing performance in any of ductility, tapping torque, torsional strength, and tension strength.

The present invention relates to a screw element (1) comprising a threaded shaft (2), a screw tip (4) formed on one shaft end and a screw head (5), formed on an opposite shaft end and with force application means (7), and comprising a screw thread (12) extending on the threaded shaft (2) and on the screw tip (4), wherein the screw tip (4) has a front tip section (4a) tapering toward the screw element end, when viewed in the screwing-in direction (Z), and a section (4b) formed on the threaded shaft with a polygonal cross section, when viewed in cross section, whose enveloping circle diameter (d.sub.h) is greater than a core diameter (d.sub.k) of the screw tip (4), and the polygonal cross section has a corner point (15) lying on the enveloping circle of the section (4b), and a front edge surface (9), radially oriented with respect to a longitudinal center axis (X-X), ends in said corner point in the sense of an increased diameter. The screw tip (4) has a first tapering tip section (4a) with a circular cross section and a second, cylindrical tip section (4c) with a circular cross section formed between the first tip section (4a) and the polygonal section (4b), wherein the screw thread (12) is continuously formed without interruption across the first and second tip sections (4a, 4c) of the screw tip (4).

A concrete screw is adapted to be driven into a hole predrilled in a concrete structure and includes a head, a shank extending from the head, a thread formed on the shank, and a plurality of bump units. The shank includes front and rear segments spaced along a longitudinal axis. The bump units are distributed on at least the front segment of the shank and staggered along the longitudinal axis. Each bump unit includes a plurality of bumps constitute an inclined pattern relative to the longitudinal axis. Each bump protrudes from the periphery of the shank. In the course of the screw being driven into the hole, the bumps pulverize concrete debris in the hole, and waste debris accumulates at a segment of the shank on which the bump units are distributed for development of a pressing segment and promotion of anti-pullout strength of the screw.

An anti-pullout and low-resistance screw includes a shank, a screw-in portion, a head portion, and a thread. The thread is helically formed around both the screw-in portion and the shank and includes a plurality of thread convolutions. Each thread convolution includes an upper tooth surface facing the head portion and a lower tooth surface facing the screw-in portion. At least one tapered pressing structure is designed on the screw-in portion and/or the shank to define at least one section with its outer diameter tapering towards the screw-in portion gradually. The tapered pressing structure extends from a bottom edge of the lower tooth surface along a longitudinal axis of the shank. The lower tooth surface has a lower tooth surface height that is greater than the thread height. An annular anti-pullout plane is formed on the shank between two adjacent thread convolutions to enhance the anti-pullout strength of the screw

A thread-forming screw which is provided in particular for thin, perforated sheet metal contains a threaded shank which below the screw head is initially configured so as to be cylindrical and then continues to a conical forming portion. The screw shank within the forming portion has a rib forming an incomplete counter thread.

The invention relates to a fastening screw, comprising an electrically insulating insulating body and a metal body formed from a metal and having an external thread. The metal body is fastened on the insulating body and has a first axial end and a second axial end opposite the first axial end, wherein the first axial end is remote from a screw head of the fastening screw. It is provided that the insulating body, by means of a shaft portion, emerges from the first axial end of the metal body along the longitudinal axis (L) of the metal body.

In one embodiment, a bone screw includes a shaft having a proximal shaft end and a distal shaft end spaced from the proximal shaft end in a distal direction along a central axis. The shaft is helically threaded between the proximal and distal shaft ends. A tip extends from the distal shaft end in the distal direction, and defines a plurality of lands with cutting flutes disposed between adjacent lands. Each land has a bore-cutting edge that extends from an inner cutting edge end to an outer cutting edge end. The inner cutting edge end is disposed at a center of the distal end of the tip, and the outer cutting edge end is spaced from the center of the distal end of the tip. The bore-cutting edges may blunt the feel of the tip so as to reduce the likelihood of soft-tissue damage.

The invention relates to a screw for cutting a thread into a component, having a shank which at least in portions is provided with a thread, a screw head having a drive configuration, the latter being adjoined by the shank, wherein, proceeding from an end of the shank that is opposite the head, first a cutting portion and then a holding portion are disposed, wherein the cutting portion and the holding portion are provided with a thread, wherein the holding portion has a larger external diameter in relation to the cutting portion, characterized in that a truncated-cone-type intermediate portion that is provided with a thread is disposed between the holding portion and the cutting portion, and in that the cutting portion has a truncated-cone-type attachment portion.

The invention is directed to a toolless screw including a body portion which comprises a shaft portion and a screw portion which includes a shank portion and a tip portion. The shank portion includes at least two helical threads which extend off the shank either at different angles, different distances, or a combination thereof. The tip portion is positioned at an end of the shank portion and has a diameter which is less than the diameter of the shank portion and extends to a point. The body portion is integrated with a screw portion at the end of the shank portion which is opposite the end where the tip portion is positioned.