A self-tapping screw includes a screw head, a screw shank having a shank body extending from the screw head along an axis, a self-tapping thread extending helically around an outer peripheral surface of the shank body and having a plurality of cutting edges continuously connected to one another and extending outwardly, radially and taperingly from the outer peripheral surface of the shank body, and a supporting unit including a plurality of supporting teeth each disposed between two adjacent ones of the cutting edges, and a plurality of concave surfaces respectively adjacent to the supporting teeth and extending inwardly from the outer peripheral surface of the shank body.

A screw having a cylindrical shank with a conical tip at one end and a screw head at the other, and at least one thread section therebetween. The thread section has a thread core. On the thread section, multiple successive thread terms are formed on a shell surface of the thread core. In the region of the thread section, multiple elevations are arranged on the outside of the shell surface of the thread core.

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 screw structure is disclosed herein. It comprises a head; a rod body integrally extended from the head and having a flat shank part and a tapered tip at a terminal of the flat shank part; a first screw thread disposed on the rod body and having a positioning tooth at a terminal thereof, a plurality of cutting units and a plurality of shaving collection spaces; a plurality of second screw threads disposed on the rod body; and a reamer thread disposed at an upper end of the rod body.

A metal anchoring fastener fastens millwork onto walls constructed with wall cladding fastened to steel studs. The load typical of a loaded cabinet is borne by the steel stud anchors owing to the mate between the profile of the steel stud anchor and the layers of millwork and wall cladding and steel stud that said anchor penetrates. The pitch of the thread adorning the profile of the steel stud anchor progresses non-linearly along the length of said shaft, the shaft is generally non-linear in profile, and the thread profile is non-uniform along the length of said shaft. The anchor can also support a secondary screw concentrically penetrating the void at the center of the anchor, in order to hang loads from a wall, with or without millwork. Predrilling of the holes can enable installation of these zinc anchors.

A screw fastener particularly adapted to improve retention while minimizing mushrooming in fibrous workpieces. A single-threaded lower portion neighbours the pointed tip of the screw and a dual-threaded upper portion neighbours the screw head. The upper portion has a first upper thread that spirals in an opposite direction to the singular lower thread, and a second upper thread that spirals in a same direction as the singular lower thread. The lower thread includes a plurality of thread turns that share a same major thread diameter while axially spanning multiple areas of the lower portion of the shaft that vary in diameter, including a bulged area, a reduced upper area of lesser shaft diameter than the bulged area at a location between the bulged area and the head, and a downwardly tapered lower area at which the diameter of the shaft narrows from the bulged area toward the pointed tip.

A screw includes a shank having a head, a point, a threaded section and a knurling section. The threaded section is located between the head and the point. The knurling section is located between the head and the threaded section. The knurling section includes a first set of grooves consisting of a plurality of first grooves and a second set of grooves consisting of a plurality of second grooves. The plurality of first grooves extends in a first angle relative to an axis of the shank. The plurality of second grooves extends in a second angle relative to the axis of the shank not parallel to the first angle. The first angle is equal to or larger than 0 degrees. The first grooves have unequal spacing. The first grooves intersect with the second grooves to form a plurality of intersecting zones with peaks and ridges of different sizes and shapes.

A quick fastening screw includes a head, a shank with spirally-disposed thread convolutions, and a drilling portion. Each thread convolution has at least three flank sections and at least three arc sections each formed between any two adjacent flank sections. Two ends of each arc section and the flank sections adjacent to the arc section are respectively intersected to thereby form two joints. Between the two joints is formed a curved cutting portion which forms a radian not more than a quarter of a maximum thread radius so that each curved cutting portion becomes sharp to cut quickly, speed up a screwing operation, decrease the friction between the thread convolutions and a workpiece, and reduce the resistance and torque. The non-circular thread convolutions also receive cut debris efficiently and prevent the cracking of the workpiece caused by the undue accumulation of the debris.

A screw, especially for wood, has a knurled region (10) with two sets (11A, 11B) of ribs (11) that are offset from each other by an azimuth angle. For example, the two sets of ribs extend towards each other from opposite ends (10A, 10B) of the knurled region (10) and are intertwined only in an overlap region (12) that is at the middle of the knurled region.

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.