An assembly for connecting a wooden sill plate to a concrete foundation slab. The assembly comprises a tapping drill bit and an anchor device. The tapping drill bit comprises a flute having a first flute section and a second flute section, the first flute section being longer and having a smaller diameter than the corresponding dimensions of the second flute section. The anchor device comprises a first anchor section and a second anchor section. The anchor device is structured such that the first anchor section is configured for embedment into the concrete foundation slab, and the second anchor section is configured for embedment in the wooden sill plate. The anchor device thereby delivers an advantageous distribution of shear forces that act on the wooden sill plate in relation to the concrete floor slab.

A panel fastener is provided that has a head having a first surface and a second surface opposite the first surface; an engagement feature on the first surface of the head, the engagement feature being configured to be engaged by a driving tool; a shank extending from the second surface of the head; a threaded portion extending from the shank, the threaded portion having first and second helical threads arranged in an intertwined manner; the first thread extending farther radially from the central axis than does the second thread; and the shank being located between the head and the threaded portion.

A threaded fastener includes an elongated body having a first end and a second end, a first portion comprising a first helical thread, with the first helical thread including a crest, a root, and flank portions, and a second, tapered portion including a second helical thread. The second helical thread includes a crest, a root, a leading flank portion, and trailing flank portion, with the leading flank portion positioned closer to the second end of the elongated body than the trailing flank portion. A thread angle of the second helical thread is larger than a thread angle of the first helical thread, and the root of the second helical thread includes a root apex formed by the intersection of the trailing flank portion and the leading flank portion.

A screw has a screw head and a shank extending downwardly from the screw head. The shank has a threaded segment, a cutting segment, and a tapered segment sequentially arranged downwardly, a thread spirally surrounding an external surface of the shank from the threaded segment to the tapered segment, multiple cutting ribs arranged around the external surface of the shank on the cutting segment of the shank, and multiple chip recesses formed between the cutting ribs. Each of the cutting ribs has a rounded crest to enlarge a drill hole and to reduce a resistance formed between the cutting ribs and the workpiece during drilling. The screw can be easily screwed into the workpiece with less driving force.

A thrust screw assembly includes a thrust screw and two threading dies for working the thrust screw. The thrust screw includes a first shank, a second shank, an external thread, and a thrust member. Each of the threading dies is provided with an external thread forming section and a flat portion forming section. In a first molding process, the first shank is worked to form the thrust member with two wing-shaped stop pieces. In a second molding process, the second shank is processed by the external thread forming section of each of the two threading dies to form the external thread on the second shank, and the two wing-shaped stop pieces is processed by the flat portion forming section of each of the two threading dies to form two flat portions on the two wing-shaped stop pieces simultaneously.

A panel fastener is provided that has a head having a first surface and a second surface opposite the first surface; an engagement feature on the first surface of the head, the engagement feature being configured to be engaged by a driving tool; a shank extending from the second surface of the head; a threaded portion extending from the shank, the threaded portion having first and second helical threads arranged in an intertwined manner; the first thread extending farther radially from the central axis than does the second thread; and the shank being located between the head and the threaded portion.

A self-drilling, self-tapping bone screw is described in which the bone screw has a drill tip free of threads and having a length at least as great as about the thickness of a proximal cortical bone layer, with the drill tip having opposed lands and a helical flute between each of the lands with each of the lands having a cutting edge configured to cut bone as the drill tip is rotated into the bone with the flutes conveying the bone debris away from the drill tip, where a lead thread begins to self-tap internal threads in the proximal cortical bone layer after the drill tip has drilled through the proximal cortical bone layer so as to avoid stripping the threads formed in the bone layer. A method of installation is also disclosed.

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 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 method for forming a stop flange on a self-tapping screw includes locating a shank of a self-tapping screw between two threading dies, fixing one of the two threading dies and moving the other one of the two threading dies to work the shank, the external thread forming section of each of the threading dies performing threading to form an external thread on the shank, inserting the insert and the recessed corner of each of the threading dies into a top of the external thread to form a groove in the shank, and the insert of each of the threading dies gradually squeezing downward an extruded portion that is formed during formation of the groove to form a stop flange on the shank. Thus, the shank is integrally formed with the stop flange, to stop an excessive movement of the external thread.