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 includes a shank having an insertion tip and a head end which has an upper portion with a cutting portion and a lower portion from which a plurality of anti-screw-out teeth protrude. Each anti-screw-out tooth includes a guide face and a stop face intersecting a circumferential surface of the lower portion for development of a recessed channel. A first thread on the shank includes a plurality of asymmetrical thread convolutions each having a first cutting face facing onto the insertion tip and a second cutting face backing onto the insertion tip. The first cutting face and a horizontal axis form an included angle between 25 and 45 degrees. The second cutting face and the horizontal axis form an included angle between 3 and 23 degrees. The screw is in favor of surface flatness of a to-be-connected plank and pull-out as well as anti-screw-out properties of the screw.

A screw having a shank, wherein the shank has a tip end, a rear end, and a longitudinal axis extending through the tip end and through the rear end, wherein the tip end and the rear end are opposite ends of the shank, and a screw thread, which is connected to the shank, and which winds around the shank, wherein a wedge groove is provided in the shank, which wedge groove winds around the shank and extends alongside at least a section of the screw thread, wherein the wedge groove is delimited by a rearwardly tapered wedge flank for wedging a grout shell surrounding the shank. At least one ridge is provided within the wedge groove, wherein the ridge compartmentalizes the wedge groove.

A screw includes a shank, a head and a drill portion joined to opposite ends of the shank, thread convolutions spiraled on the shank, ribs protruding from the shank, a discharging portion formed between any two adjacent ribs, and cutting portions formed on the thread convolutions. Each thread convolution has two thread flanks converging at a thread crest and forms respective thread roots by which different vertical distances are defined. One of the thread flanks includes flank sections having different flank angles. Therefore, the thread convolutions are asymmetric. The discharging portion has two inclined surfaces connected to the ribs and an accommodation groove formed therebetween. The cutting portions and ribs serve to cut and cooperate with the asymmetric arrangement to increase the cutting efficiency, thereby reducing screwing resistance, enhancing pull-out resistance whereby the screw is not easily pulled out of a workpiece, and removing chips quickly through the discharging portion.

A screw includes thread convolutions spirally disposed around a shank. Each thread convolution has a thread crest formed along a junction of opposite upper and lower thread flanks. Notches are recessed into the thread crest of at least one thread convolution. Each lower thread flank includes a first lower flank section and a third lower flank section extended in a curved manner and includes a second lower flank section extending between the first and the third lower flank section in a non-curved manner. Accordingly, the third lower flank section cuts a workpiece sharply and allows cut chips to travel along the first lower flank section, the third lower flank section, and the notches, thereby attaining a quick removal and proper accumulation of chips. The second lower flank section provides supporting force, thereby increasing the strength of the thread convolutions, improving the cutting capability, and reducing the screwing resistance.

A tapping screw and a method of manufacturing the tapping screw are disclosed. The tapping screw may include a head part and a screw part that is beneath the head part and that has a thread on an outer periphery of a minor diameter circle thereof, wherein the screw part has a receiving groove on a portion thereof to receive by-products from a body as the screw part progresses through the body.