A screw includes a head having a top face and a conical bottom surface, a shank, and thread convolutions. A chip guiding channel is recessedly formed on the conical bottom surface. On the conical bottom surface are spirally disposed a cutting portion which has a plurality cutting units sequentially arranged in a spiral manner, thereby allowing the chip guiding channel to be surrounded by the cutting units along a spiral track. The spiral arrangement of the cutting units assists the head in cutting fibers of a workpiece which are wound around the head into small chips in a continuous and spiral severing manner to reduce drilling torque and resistance, and the spirally-defined chip guiding channel also facilitates a smooth removal of the chips, thereby allowing the head to fit level with a top surface of the workpiece and increasing a fastening effect.

A self-tapping screw for use in securing at least two materials together. The self-tapping screw may include a screw cap that receives a screw body to reinforce the strength of the screw head. The screw cap is composed of a zinc-aluminum alloy that may be die casted and provides additional strength and hardness to the attached screw body. The screw cap has a rolled flange that helps to securely retain the flat rim of the attached screw body.

A fastener may include an elongated shank, a head at a distal end of the shank, and a drill point at a terminal end of the shank, which is opposite to the distal end. The fastener may include a primary thread starting at the drill point and extending along the shank towards the head. The fastener may include a secondary thread starting at the drill point, extending along the shank towards the head, and stopping in an axial direction before the primary thread ends. The secondary thread may be radially located 180 degrees from the primary thread. The drill point may include a plurality of radially extending cutting edges and one or more relieved flute portion extending along the surface of the drill point.

Self-drilling, self-tapping and self-advancing orthopedic screws are provided. An orthopedic screw includes a relief cut at the tip of the screw that is timed to the distal-most thread at the end of the screw tip to create a wide and sharp cutting edge for the screw.

A gradient insulation screw (1) for adjustable fastening of a roofing membrane (2) on a substrate, in particular a steel sheet (3), the gradient insulation screw (1) comprising a drilling tip (4) with a first direction of rotation; following the drilling tip (4), an assembly thread (7) with a second direction of rotation, which differs from the first direction of rotation; following the assembly thread (7), a first thread-free region (8); following the first thread-free region (8), an adjustment thread (9) with the first direction of rotation, the outer diameter of which is greater than the outer diameter of the assembly thread (7) and the drilling tip (4); and following the adjustment thread (9), a tool holder (10) as well as a system (11) for adjustable fastening of a roofing membrane (2) on a substrate with a gradient insulation screw (1) and a holding element (12) and a method for adjustable fastening of a roofing membrane (2) on a substrate using such a system (11).

A fastening arrangement including a grommet, which is configured as a substantially cylindrical sleeve with a head part, with a hollow-cylindrical shaft and with a conical tip, and also a fastener and a nut, for example made of plastic, which is fitted on the first threaded portion of the fastener. The fastener has two threaded portions, wherein one threaded portion is configured as a right-hand thread and the other threaded portion is configured as a left-hand thread (or vice versa). Moreover, the invention comprises a mounting method for such a fastening arrangement, in which the setting operation (anchoring of the fastener, adjustment of the sheath) can be managed in one step without changing the driving direction of the setting tool.

A drill bit structure of a self-tapping screw is rotated clockwise to screw with a workpiece or is rotated counterclockwise to remove from the workpiece, and the self-tapping screw contains: a head, a shank, and a drill bit. The head is configured to connect with a tool. The shank integrally extends from the head. A conical face has a tip, two arcuate grooves, and two first cutting edges. Each of the first cutting edges is formed on a connection portion of each arcuate groove and the conical face. The drill bit includes two third cutting edges, and each third cutting edge is adjacent to the tip, shapes of the two first cutting edges correspond to shapes of the two third cutting edges respectively, and heights of the two first cutting edges are not less than the conical face. Each first cutting edge has a reinforcement portion.

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.

Various embodiments provide a post-to-beam fastener including a head, a tip, and a threaded shank connected to the head at a first end and the tip and a second end. In various embodiments, threaded shank includes a longitudinal axis extending from the head to the tip, and the tip includes a recess operable to removably receive a drill bit to the fastener.

A method of manufacturing a drill comprises providing an elongate element defining a longitudinal direction and having, in the longitudinal direction, a front end, an intermediate section, and a rear end opposite to the front end; forming by cold forming only, at the front end, a drill tip having a cutting edge; and, forming by cold forming only, on the intermediate section, a channel extending along the longitudinal direction.