A screw with multiple thread angles includes a shank, a main threaded portion having thread convolutions, and a head. Each thread convolution defines different thread angles from a root to a thread crest in sequence, namely a first thread angle ranging between 70 degrees and 75 degrees, a second thread angle ranging between 37 degrees and 43 degrees, and a third thread angle ranging between 20 degrees and 23 degrees. Notches are recessed into the thread crest for attaining a smooth removal of cut chips. The third thread angle assists each thread convolution in cutting a workpiece sharply to facilitate a quick cutting operation. The second thread angle and the first thread angle help widen a cutting track caused by the cutting operation gradually so that the thread convolutions are continuously drilled into the workpiece by a multi-stage reaming and drilling operation to achieve a quick screwing effect.

The invention relates to a screw (1), having a shank (3) which is provided with a thread (2) with at least one asymmetrical thread turn (4) with a plurality of windings, wherein the thread has an external diameter (Da), a core diameter (Dk) and a thread pitch (P), wherein the thread turn (4) has thread flanks (7, 8) with a flank angle (phi), wherein the thread flanks (7, 8) have a load-bearing flank (7) and a counter-flank (8) which abut one another directly or indirectly in a thread bottom (9) and at a thread tip (10), and wherein a flank angle (phiL) of the load-bearing flank (7) is smaller than a flank angle (phiG) of the counter-flank (8). The flank angle (phiL) of the load-bearing flank is at least 25°, preferably from 25° to 35°, in particular 30°, and the flank angle (phiG) of the counter-flank is at least 40°, preferably from 40° to 60°, in particular 50°, wherein the flank angle (phi) is from at least 65° to at most 95°. Screws of said type are used, in particular, for direct screw connection in light metal cast components.

A tolerance compensation element that compensates for tolerances in the distance between first and second components, includes a thread bolt having a first drive feature, a first thread of a first thread direction and a second thread of a second thread direction. Between the first and the second thread, a protrusion extends from the thread bolt radially to the outside. The element includes a first plastic overmold in the portion of the first thread, which provides a fastening structure for the fastening to the first component, and a second plastic overmold around the protrusion which extends radially to the outside, to provide an abutment portion abutting the second component when in use. A distance of the second plastic overmold to the first plastic overmold is changeable after overcoming a start-up torque between the first plastic overmold and the first thread in longitudinal direction of the thread bolt.

A cement board screw a high thread that begins on the tapered end, extends onto the shank and terminates at a second axial location along the shank. The high thread defines a high peripheral edge, where a leading flank and a trailing flank meet at the high peripheral edge and together define a high thread angle that is between about thirty degrees and about fifty-five degrees. A low thread begins on the tapered end, extends onto the shank and terminates substantially at a first axial location along the shank such that an axial length of the low thread is less than an axial length of the high thread. The low thread includes a leading flank and a trailing flank that meet at a low peripheral edge and together define a low thread angle that is between about fifty degrees and about seventy degrees.

A fastener includes a shank having a first end and a second end defining a length. The fastener includes a thread provided on the shank, the thread including a first region adjacent to the first end and a second region between the first region and a head at the second end, the thread includes a leading edge and a trailing edge, each edge forming an angle with a surface of the shank, the leading edge forming a non-normal angle with the surface of the shank and the trailing edge forming an angle about normal to the surface of the shank. The fastener may include an arcuate detent region in the shank between respective turns of the thread, the detent region having a length, the length decreasing from the first end toward the second end between the respective turns. The fastener may include a plurality of flutes positioned along a length of the shank.

A self-tapping screw includes a head portion, a lower side thereof configured with a screw rod, a front end thereof configured with a drill tail, a first thread segment formed on a front end of the screw rod above the drill tail, a second thread segment with at least two threads formed on a rear end of the screw rod immediately below the head portion, a crest angle of any one of the threads of the second screw segment being 1.15 to 1.2 times of a crest angle of any thread of the first thread segment, and a thread root diameter of the second thread segment increasing proportionally with the crest angle of the second thread segment. Whereby, the present invention provides a self-tapping screw capable of tight locking without idling.

The invention provides a low-wear screw structure which comprises a screw head, a rod body, a first thread and at least a crushing rib, wherein the rod body extending out from the screw head and being successively formed with a rod extension part, a reaming part and a taper part, the first thread being annularly arranged on an outer peripheral surface of the rod body at a distance from the taper part to the rod extension part through the reaming part, the crushing ribs being arranged on the rod body at the reaming part, wherein a first included angle is formed between the first side surface and the outer peripheral surface of the rod body, a second included angle is formed between the second side surface and the outer peripheral surface of the rod body, and the first included angle is different from the second included angle.

A wood screw includes a head, a shank axially extending from the head, a main thread extending helically around the shank in a tightening direction and having an outer diameter ranging from 3 to 16 mm, and a plurality of forward ribs extending spirally around the shank in a same direction as the main thread. The number of the forward ribs ranges from three to five. Each forward rib, in a cross section thereof, has a first outer edge facing the tightening direction, and a second outer edge facing opposite the tightening direction and having a length shorter than that of the first outer edge. Each forward rib has a height smaller than that of the main thread, and a lead angle greater than that of the main thread.

A fastener has a head and a shank extending from the head to a tip. The shank has a threaded distal portion that includes primary threads defining a major diameter, a minor diameter, and at least one helical rib or scalloped surface at the minor diameter. The at least one rib extends between adjacent primary threads of the threaded portion and extends in a helical configuration. The configuration of the fastener with helical ribs in the minor diameter reduces contact surface area between the fastener and building material substrate, like wood, during installation of the fastener, which thereby results in less torquing force required for installation.

A screw (1) is proposed, which has a shank (4) having a longitudinal axis (12), which has a first end (9) and a second end (17), the shank (4) having at least one thread (5) at least to some extent, the thread (5) having a thread groove (6), which has a thread ridge (7), a thread valley (8), a thread depth resulting from the thread ridge (7) and the thread valley (8), a flank (10) facing the first end (9) of the shank (2) and a flank (11) facing away from the first end (9) of the shank (2), a flank (10), from the thread valley to the thread ridge (7), facing the first end (9) of the shank (2) having at least two different angles enclosed between the longitudinal axis (12) and the flank (10) and/or a flank (11), from the thread valley (8) to the thread ridge (7), facing away from the first end (9) of the shank (2) having at least two different angles enclosed between the longitudinal axis (12) and the flank (11), the angle (20) enclosed in the thread valley (8) of a flank (10) facing the first end (9) of the shank (2) being shallower than the angle (21) enclosed at the thread ridge (7), and/or the angle (22) enclosed in the thread valley (8) of a flank (11) facing away from the first end (9) of the shank (2) being shallower than the angle (23) enclosed at the thread ridge (7), as a result of which, easy screwing of the screw (1) according to the invention into a mating part becomes possible and self-locking prevents loosening of the screw (1) according to the invention.