Abstract: 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.

Abstract: A welding mechanism for welding different blank sections includes a welding device and a carrier. The carrier has a base, two opposite positioning members, an operating set disposed between the positioning members and driven by a power source, and a holding member and a pushing member which are respectively disposed relative to the positioning members. The blank sections, including a front section and a rear section, are separately placed on the operating set. The front section is restricted by the holding member. The pushing member pushes the rear section, so the two sections meet at a joint. When the two sections rotate synchronously along with the rotation of the operating set, the welding device welds the two sections at the joint circumferentially to produce a bi-compositional screw, thereby preventing the generation of air and pores inside the joint after welding, increasing processing quality, and reducing processing costs.

Abstract: A self-drilling screw includes a leading section having a drill body and opposite discharge grooves formed on the drill body. The drill body and the discharge grooves meet at cutting edges. On the drill body are formed two blade portions connected to the cutting edges and tapering at respective second tips. The blade portion has a second included angle of not more than 50 degrees. Between the blade portions is formed a drilling portion terminating at a first tip and having a first included angle of not more than 60 degrees. Two opposite concave surfaces each extend from the drilling portion to each blade portion. The first tip and the second tips are situated at different places. Accordingly, the end of the leading section presents a shape of a curved bow riser to cut quickly and help quick removal of chips, thereby decreasing resistance and preventing the cracking problem.

Abstract: A screw capable of reducing drilling torque includes a shank provided with cutting threads, and a head and a drilling portion respectively formed at two ends of the shank. Each cutting thread has two opposite flank surfaces converging at a thread crest. On the thread crest are recessedly formed notches alternating with grooves. Each groove has an upper crest edge and a lower crest edge meeting the flank surfaces respectively. Each notch has a first cutting edge and a second cutting edge meeting the flank surfaces respectively. The above cutting edges and crest edges cooperate to provide multiple cutting points, thereby increasing the cutting efficiency, preventing the improper entanglement of fibers, and reducing drilling torque for easier screwing. The notches and grooves accommodate and press partial debris for achieving a stable and tight engagement between the screw and an object and increasing the ability of resisting the pulling-out force.

Abstract: A screw includes a shank, a head connected thereto, a drilling portion opposite to the head, a first threaded section spirally formed on the shank, and a leading threaded section spirally extending upwards from the drilling portion. The two threaded section are disconnected so that a valley is formed between them. At least one cutting unit protrudes from the valley and has two ends connected to the first threaded section and the leading threaded section respectively. The leading threaded section assists the drilling portion in cutting and drilling into an object while screwing, and the cutting unit protruding from the valley severs fibers which are not cut by the leading threaded section completely to prevent the entanglement of the fibers. The valley helps accommodate and evacuate cut chips. Therefore, the drilling resistance is reduced effectively to increase the screwing efficiency.

Abstract: A fastener includes a shank, a head connected thereto, a drilling portion opposite to the head and a plurality of first threads and second threads spirally disposed on the shank. The second threads are affixed to the first threads and provided with a plurality of opening slots defined thereon. The opening slots expose portions of the first threads therethrough. The first threads divide the shank into a plurality of shank segments, each of which has a base part and a transition part extending outward from the base part to be inclined by 5 to 10 degrees. The opening slots formed on the second threads provide an auxiliary cutting effect and accommodate cut debris. The first threads reinforce the bearing and drilling force of the second threads. The inclined transition part helps increase the ability of resisting the driving torsion and attain an anti-loosening force, thereby increasing the fastening effect.

Abstract: A screw capable of drilling and cutting includes two inclined cutting planes with a cutting edge formed on a convergence of the cutting planes. A tapered positioning member extends from the convergence of the cutting planes, where the cutting edge is divided into dual sub cutting edges by means of the positioning member. Each sub cutting edge has an inclined angle. An included angle included by the sub cutting edges is smaller than 180 degrees. Threads spiral on a shank and extend to the sub cutting edges. Setting the positioning member against on an object permits a steady performance during the first stage of screwing. Subsequently, the sub cutting edges provides a scraping effect on the object during drilling. Torque is reduced and drilling speed is promoted.

Abstract: A fastener capable of speedily screwing provides a plurality of blocks on a bottom surface of a head and an accommodating area formed between any two adjacent blocks. Each block includes a first wall arranged at one side of the accommodating area and extended upward from the bottom surface, a second wall extending from the first wall to the other side of another adjacent accommodating area, and a cutting edge formed at a convergence of the first wall and the second wall. In screwing, the blocks assist in cutting to achieve a speedy screwing effect, and the accommodating area allows the cutting debris generated accordingly to be received therein to remain a firm engaging force between the fastener and an object. Further, there is no extra cutting debris protruding out of the object after screwing, which increases the flatness, and also enhances the screwing force of the fastener.

Abstract: A fastener capable of speedily screwing provides a plurality of blocks on a bottom surface of a head and an accommodating area formed between any two adjacent blocks. Each block includes a first wall arranged at one side of the accommodating area and extended upward from the bottom surface, a second wall extending from the first wall to the other side of another adjacent accommodating area, and a cutting edge formed at a convergence of the first wall and the second wall. In screwing, the blocks assist in cutting to achieve a speedy screwing effect, and the accommodating area allows the cutting debris generated accordingly to be received therein so as to remain a firm engaging force between the fastener and an object. Further, there is no extra cutting debris protruding out of the object after screwing, which increases the flatness, and also enhances the screwing force of the fastener.

Abstract: A wood screw provides a plurality of auxiliary cutting areas disposed on a bottom surface of a head and a flat area formed in any two adjacent auxiliary cutting areas. Each auxiliary cutting area includes at least two cutting grooves disposed at intervals and formed on the bottom surface, and a cutting edge formed at a convergence of the connective cutting grooves. When the bottom surface contacts the surface of the wood, the cutting edge cuts and scrapes off burrs generated around the drilling hole, and the scraped burrs are accommodated in the cutting grooves to prevent the burrs from exposing to the head after screwing. Further, the head is tightly screwed on the wood to enhance the screwing stabilization.

Abstract: A screw capable of drilling and cutting includes two inclined cutting planes with a cutting edge formed on a convergence of the cutting planes. A tapered positioning member extends from the convergence of the cutting planes, where the cutting edge is divided into dual sub cutting edges by means of the positioning member. Each sub cutting edge has an inclined angle. An included angle included by the sub cutting edges is smaller than 180 degrees. Threads spiral on a shank and extend to the sub cutting edges. Setting the positioning member against on an object permits a steady performance during the first stage of screwing. Subsequently, the sub cutting edges provides a scraping effect on the object during drilling. Torque is reduced and drilling speed is promoted.

Abstract: A saw tooth screw provides a screw thread divided into a first and a second thread sections. A plurality of slots, inclined with respect to a shank axial line, are disposed on each thread of the first thread section for dividing the thread into a plurality of thread segments, wherein each of the thread segment has a first inclined surface and a second inclined surface on two ends thereof; the first inclined surface is parallel to the second inclined surface. The thread of the second thread section is formed of a saw-tooth-shape by having recesses extending from a shank to an outer edge of the thread for debris of object to exit through the slots, thereby reducing the screwing torsion and increasing the screwing rotation speed.