A screw structure is disclosed herein. It comprises a head; a rod body integrally extended from the head and having a flat shank part and a tapered tip at a terminal of the flat shank part; a first screw thread disposed on the rod body and having a positioning tooth at a terminal thereof, a plurality of cutting units and a plurality of shaving collection spaces; a plurality of second screw threads disposed on the rod body; and a reamer thread disposed at an upper end of the rod body.

A screw includes a head and a shank extending from the head, and a hole-enlarging portion formed on the shank. The hole-enlarging portion features no thread and a substantially triangular transverse section. The hole-enlarging portion includes three inclined edges spaced from one another in the circumferential direction of the shank, and a guiding slope is formed between two adjacent inclined edges. The shank defines a longitudinal axis and is provided with a thread. Each inclined edge extends toward the head in an inclined direction relative to a horizontal axis perpendicular to the longitudinal axis. The inclined direction of each inclined edge is identical to a direction in which the thread extends toward the head.

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 screw includes a shank with an outer periphery, a head connected to the shank, and thread convolutions spiraling around the shank in a right-hand direction. The outer periphery defines opposite first and second peripheral envelope surfaces. A cutting slot unit is formed on the shank and arranged on the first peripheral envelope surface. The cutting slot unit includes a first cutting slot with two first edges and a second cutting slot with two second edges. The first edge extends in an extension direction opposite to the right-hand direction. One first edge of the first cutting slot is parallel to one second edge of the second cutting slot . The opposite extension of the cutting slot unit assists the screw in screwing quickly, attains quick removal of chips, and increases the fastening effect by pressing chips downwards.

Described is a masonry fastener, comprising: a shank having a first and second portions and a first and second end, the shank having ductility measured as the bending angle under complete three repeated cycles without rupture of between about 10.0° and 22.0°; the first portion having a tapered helical screw portion along a predetermined longitudinal length thereof, the tapered helical screw portion commencing at a tip of the first end thereof and ending at an end of the second portion; and the second portion having a tapered helical screw portion along a predetermined longitudinal length thereof, the tapered helical screw portion commencing at an end of the first portion and ending at the second end.

A thrust screw includes a head, a first shank, a second shank, and a drilling member. The first shank and the second shank are arranged between the head and the drilling member. The second shank is provided with an external thread. The first shank is provided with a thrust member corresponding to the external thread. The thrust member includes two wing-shaped stop pieces and two flat portions. The two flat portions are formed on the two wing-shaped stop pieces respectively and correspond to the external thread. The two flat portions have an outer diameter greater than that of the external thread. The two flat portions of the thrust member stop a further screwing motion of the external thread.

A screw having a cylindrical shank with a conical tip at one end and a screw head at the other, and at least one thread section therebetween. The thread section has a thread core. On the thread section, multiple successive thread terms are formed on a shell surface of the thread core. In the region of the thread section, multiple elevations are arranged on the outside of the shell surface of the thread core.

A wood screw, including a cylindrical screw shank, at the end of which there is formed a tip, a screw head, which is formed at the other end of the screw shank, as well as a threaded section, which extends from the tip in the direction of the screw head, wherein the threaded section has a thread core and a thread winding having several threaded turns circulating the thread core, wherein several successive threaded turns have projections, which are formed alternatingly in essentially the direction of the screw head and in essentially the direction of the tip.

A screw structure is disclosed herein. It comprises a head; a rod body integrally extended from the head and having a flat shank part and a tapered tip at a terminal of the flat shank part; a first screw thread disposed on the rod body and having a positioning tooth at a terminal thereof, a plurality of cutting units and a plurality of shaving collection spaces; a plurality of second screw threads disposed on the rod body; and a reamer thread disposed at an upper end of the rod body.