Abstract: A screw with protruding sheets on a head portion comprises a thread portion; a screw tail at one end of the thread portion, a slot formed on the screw tail; a plurality of screwing sheets formed at another end of the thread portion; a plurality of recesses formed between the plurality of screwing sheets for removing undesired pieces; a drilling head being formed at front ends of the screwing sheets; the drilling head formed with a plurality of protruding sheets made of soft metal. By screwing the screw by rotating from the slot, the screw will rotate so as to drill a hole and enter into a wood plate. Then the protruding sheets enlarge the hole. The undesired wood pieces are removed from the recesses. When the screw further drills into a metal plate, the protruding sheet will be worn out because the protruding sheet is made of soft metal.

Abstract: A self-threading screw is described which includes a (basically) conical point set at the end of its shank opposite that where the head is housed, and a sunken zone set between the end of the screw shank and the conical point. In addition, an apparatus is described to produce a self-threading screw provided with a point and a sunken zone, in which at least the thread of the self-threading screw, the conical point and the sunken zone are simultaneously produced by rolling.

Abstract: A wood screw is provided which can be smoothly driven in with a small driving force. Helical ribs that are the highest at the center and gradually lower toward both ends are formed on the outer periphery of the tip of a shank having threads on the outer periphery at intervals of 180° in the circumferential direction. Each helical rib is a discontinuous body formed by a plurality of protrusions having different heights. This reduces the turning resistance imparted to the helical ribs, thereby reducing the driving force required.

Abstract: A self-drilling/self-tapping screw comprises a shank having a plurality of self-tapping thread convolutions thereon and a head on an end of the shank. The shank further includes a longitudinal axis about which the shank rotates and an entering end portion on another end thereof. The entering end portion comprises a sharp pointed tip substantially located on the longitudinal axis of the shank, a first cutting edge has a first acute angle with the longitudinal axis of the shank, and a second cutting edge having a second acute angle with the longitudinal axis of the shank, the second acute angle being smaller than the first acute angle. In an embodiment, a groove is provided in the entering end portion to increase the cutting speed.

Abstract: Screw having quick drilling speed and smoothened expulsion of chips. The normal thread formed on the stem of the screw directly extends through the conic section of the tail end of the screw to the tip thereof by a larger guide angle. The thread between the changing point of the guide angle of the thread and the tip of the conic section serves as a thread with cutting/drilling and chip-expelling function. Therefore, the cutting/drilling and chip-expelling thread of the screw is directly formed by means of changing the guide angle of the normal thread of the screw.

Abstract: A cutting insert for fasteners having a shape with an outline conforming to at least a portion of a contour of a cross-section of on end of on fastener. The insert being made of a material sufficiently strong to provide for self-tapping in application of the fastener.

Abstract: A self-tapping screw (1) consists of two interconnected sections (7 and 8) of stainless material. The first section (7) comprising the tool access (4) and the thread (6) consists of stainless, austenitic steel and the second section (8) configured as a boring part (5) consists of martensitic steel.

Abstract: A self-drilling screw (10) for use in steel houses has a leg (11), one end of the leg being formed as a drilling portion (12), the other end continuing to a flathead (13) through a neck (16) disposed close to the flathead (13). A tapping thread (14) formed around the leg continue from drilling portion, with a guiding thread (15) continuing from the tapping thread. A fastening thread (17) formed around the neck has a larger diameter than tapping and guiding threads (14, 15), the neck (16) being a thickened portion of the leg (11). A recess (18) formed in flathead (13) to engage with a driving tool is defined by and between torque-receiving walls (19) extending in parallel with the screw axis and beyond a boundary between the flathead (13) and neck (16), so that a driver can fit in the recess of such a thinned flathead to transmit a strong torque to tighten the screw into a steel panel, without any fear of caming-out problem.

Abstract: A screw includes a shank having a head end part, a tapered insert end part, and a surface that is formed with a screw thread that spirals downwardly along an axis of the shank. The insert end part has a surface formed with a flute. The flute has an upper end portion that extends to interrupt a portion of the screw thread, and is defined by two confining side walls which extend radially from the axis of the shank and which form an angle ranging from 90° to 180° therebetween. The upper and lower end portions of the flute have a depth that gradually increases toward an intermediate portion of the flute.

Abstract: A wood screw is provided which can be smoothly driven in with a small driving force. Helical ribs that are the highest at the center and gradually lower toward both ends are formed on the outer periphery of the tip of a shank having threads on the outer periphery at intervals of 180° in the circumferential direction. Each helical rib is a discontinuous body formed by a plurality of protrusions having different heights. This reduces the turning resistance imparted to the helical ribs, thereby reducing the driving force required.

Abstract: A threaded screw with cutting notch structures thereon comprising a screw body and a plurality of screw threads provided along the screw body, characterized in that at least two notches, corresponding to each other are provided at the front end of the screw body, the interior space of the notch is tapered upward from the bottom forming into a slanting cut face and a cut wall, and the slanting cut face is corresponding to the cut wall and forming an inclination angle of 91 to 119 degree, thereby when the end portion of the first screw thread is screwed into a locking element, the screw threads are easily screwed in the locking element with the cut wall cuts the locking element and the debris of the locking element can be expelled by the space of the cutting notch and a lower resistance allowing a faster screwing process into the locking element.

Abstract: A flat headed screw structure includes a screw body having an axle face formed with an axially extended thread, and having a tail end provided with at least one cut groove. The cut groove has a top defining a cut groove opening. The cut groove opening further defines a scrap draining chute toward a center of the screw body. The scrap draining chute extends into the inner portion of the screw body and exceeds the central line of the screw body through a predetermined angle, thereby preventing scraps from blocking the cut groove opening.

Abstract: The present invention relates to a self-drilling and thread-forming connecting element, a screw, having a threaded shank and a drilling point at the end for the chip-forming drilling of a core hole for the threaded shank. The drilling point is designed as a step drill having at least two drilling steps with different diameters.

Abstract: A screw device with an elongated shank, a self-tapping cutter located thereon on and with a cutting head within which there are two equivalent and opposing grooves the angularity of which with reference to horizontal is the same and equivalent to the angular pitch of the threading about the shank and with serrated edging about the bottom side of the cutting head and in the top side of the cutting head there being found a closed hole.

Abstract: A screw has a shank portion (20) provided with a thread (21) and passing over via a transition into a conical tip (22). One or more parallel fins (24) are provided at least in the area of the tip. They are formed with cutting edges (23) and preferably disposed at an angle of inclination (13) of no less than 5° with respect to the longitudinal axis of the screw. The fins (24) project beyond the core diameter (1) of the shank portion (20). The conical tip (22) includes a finless end portion (26). The thread (21), however, extends across the full length of the tip (22).

Abstract: An elongate roof bolt includes a bolt body having an axially extending central bore and defining a leading end. The leading end includes a pair of axially extending abutment elements formed by machining. Each abutment element includes an abutment face for engagement with a drill tip on opposite sides thereof, to transmit rotary forces during drilling. The drill tip extends across the leading end of the bolt body and is bonded to the abutment elements by welding, soldering or brazing. The bore opens out of said bolt bonded adjacent said leading end.

Abstract: An anchor has a hollow shank having a head at one end and an integral blade portion at the other end and formed with male threads on the outer periphery. Cuts are formed in a peripheral wall of the hollow shank to define therebetween a bendable portion adapted to bend when pushed out by a mounting screw driven into the hollow shank. The blade portion is substantially semicylindrical with side edges defining cutting edges. Ribs for inclining the mounting screw are formed on the inner surfaces of the blade portion and the hollow shaft, respectively. When a mounting screw is driven through the article into the anchor to fix an article to the board, the mounting screw is inclined relative to the anchor, so that the bendable portion is pushed out, thus preventing the anchor from rotating together with the screw.

Abstract: A fastening screw having an elongate shank (1), and a drilling tip (2) and a head (3) provided at respective opposite ends of the shank (1). The drilling tip (2) has a cutting edge (5) for cutting through metal and a flute (6) extending longitudinally of the shank (1). A thread (8) is formed on the shank (1) and extends over a portion of the section of the shank (1) in which the flute (6) is formed. A method of forming a fastening screw from a screw preform (9), includes deforming the preform (9) to create a drilling tip (2) which has at least one cutting edge (5) and a flute (6), and applying a thread (8) to the shank (1) in the region in which the flute (6) is formed.