A screw contains: a head, a shank, and a tip. The head is configured to connect with a tool. The shank integrally extends from the head. The shank includes a screwing thread and a central axis. The tip is conical and includes a first segment and a second segment, wherein a diameter of the tip gradually decreases from the first segment to the second segment. The tip has a cone angle which is within 5 degrees to 30 degrees. The tip includes a conical drill portion having a pointed section away from the central axis. The tip further includes two chip elimination slots of different sizes, wherein two drilling edges are asymmetrical, and two cutting edges are asymmetric and are defined among the two chip elimination slots and the tip. The tip further includes a threaded guide section separated by the two chip elimination slots.

Presently disclosed is a standoff fastener for use in a compound floor structure. The threaded fastener includes a threaded standoff portion designed to accept a nut which has a diameter larger than a head portion of the standoff fastener. The head portion is located centrally within the fastener in order to reduce a tendency of the fastener to pivot within a driver during the fastening process.

A roof cover fastener may include a cover plate having a planar body with a perimeter. A central aperture may be disposed centrally in the body. A first annular rib may be formed into the body and may encircle the central aperture. A second annular rib may be formed into the body and may encircle the first annular rib. A first channel may separate the first annular rib from the second annular rib. A medial aperture may be disposed in the channel between the first annular rib and the second annular rib. Optionally, the fastener may also include an auger element having a first end and a second end. A head may be coupled to the first end, and a tip may be coupled to the second end. A thread crest with a thread root may extend from the second end towards the first end.

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 self-drilling ground screw for electrical grounding. The self-drilling ground screw includes a shaft having a proximal end and a distal end, wherein a head is affixed to the proximal end. The shaft further includes a threaded portion and a drill bit portion thereon, wherein threading is disposed about the shaft along the threaded portion. The drill bit portion includes spiral cutting edges therealong. A protrusion extends from the distal end, wherein the protrusion tapers to a point.

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.

A self-drilling screw includes a shank and at least one thread. The shank includes a self-drilling portion, a head portion spaced from the self-drilling portion along a longitudinal axis, and a straight rod portion between the self-drilling portion and the head portion. The thread is spirally formed on the straight rod portion and includes a plurality of thread convolutions. Each thread convolution is provided with three to eight recesses spaced apart circumferentially, and a screw thread portion is formed between two adjacent recesses. The recess features a recess length circumferentially, and the screw thread portion features a screw thread length circumferentially. The screw thread length is 25% to 200% of the recess length. The self-drilling screw can be driven into articles to be fastened quickly without loss of binding forces between the self-drilling screw and the articles.

A self-drilling screw, particularly for use in a security screen employing leveraged clamping. The self-drilling screw comprises a head and a shank. A drill bit is formed at one end of the shank away from the head with a thread extending along the full length of the shank, including the drill bit. The thread on the drill bit increases holding strength.

A wood screw that includes a head and a shank is revealed. The shank is formed by a main shank portion and a tapered portion whose diameter is smaller than that of the main shank portion, both provided with a locking thread. A plurality of drilling units, whose outside diameter of the drilling unit is smaller than that of the locking thread, is disposed on the tapered portion. The drilling units first destroy workpiece material corresponding to the main shank portion so that the workpiece material becomes loose and the resistance of the locking thread of the main shank portion is reduced. Thereby the wood screw is screwed into the workpiece more smoothly. Moreover, an internal thread segment whose thread depth matches that of the locking thread of the main shank portion is formed so that the wood screw and the workpiece are fastened more firmly.

The invention relates to a cooking oven comprising at least two entities made of sheet metal (2, 3), each sheet metal entity (2, 3) comprising at least one surface carrying an enamel layer, specifically a vitreous enamel layer, said enamelled sheet metal entities (2, 3) overlapping each other and a screw connection for grounding and coupling said enamelled sheet metal entities (2, 3), wherein a ground element is at least indirectly coupled with one of said enamelled sheet metal entities (2, 3) for grounding said stack of enamelled sheet metal entities (2, 3), wherein at least one screw (5) with a screw shaft (5.1) is provided through said enamelled sheet metal entities (2, 3), wherein the screw (5) is at least indirectly electrically coupled with the ground element and said screw shaft (5.1) comprises a thread for providing an electric coupling between the enamelled sheet metal entities (2, 3).