Abstract: A self-drilling reaming screw for hard materials such as hard woods or plywood boards each covered with a rigid surface layer has a threaded portion (8) continuing to a drill bit (7), and a non-threaded shank (3) continuing from the threaded portion. The screw has also a conical head (4) continuing from the shank, and a reaming portion (6) is composed of blades protruding out from the shank in opposite radial directions, with each blade (6) being so thick as to be protected from the hard materials (21). The reaming portion has a diameter (W) smaller than but close to the diameter (D) of conical head, and larger than but not close to the diameter (d) of threaded portion. The drill bit (7) forms a rough hole (23) that is then tapped by the threaded portion (8) to give a female-threaded hole (24). The reaming portion (6) enlarges the threaded hole to form a guide hole (25), such that the conical head (4) is forced into it and buried in the hard material.

Abstract: The main body (2) of a self-drilling screw has a driven head (9) having at its top central region a weld lug (10) of a prescribed size. The screw also has a discrete drive head (3) having in its top a hole (11) for engagement with a driving tool. A thinned stud (12) continuing from the drive head (3) is resistance welded to the top center of driven head (9), using the weld lug (10) to form between these heads a torque-limiting junction (13) ready to break at a prescribed torque. As the main body (2) of the screw for use with thin steel sheets is tightened, the drive head (3) will be removed due to breakage of the junction (13). Any excessive tightening torque imparted to the screw will not break a female-threaded hole formed in the steel sheet, but firmly retaining the screw on it.

Abstract: A heat-resistant self drilling tapping screw adapted for drilling a stainless steel plate is proposed, which heat-resistant self drilling tapping screw has no delayed fracture and can satisfy high corrosion-resistivity and high tensile force. The heat-resistant self drilling tapping screw for drilling a stainless steel member, which includes a drill part 4, a tapping screw part 5 connected to the drill part 4, a fastening screw part 6 connected to the tapping screw part, and a screw head part 3 for conducting and providing a turning force; where the drill part 4 and the tapping screw part 5 are made of a high-carbon chrome series stainless steel, and the fastening screw part 6 including the screw head part 3 is made of a nickel series stainless steel.

Abstract: A self-piercing nut for use with relatively thick metal panels has four independent posts (9) formed integral with respective corners of a nut body (2) and providing four seat faces (10). The pilot portion (6) has an end face (7) for punching a hole in the panel is projected beyond the seat faces, and the nut body (2) is a pressed boron steel article entirely hardened by the quenching method so as to show a strong piercing force. Height ‘H’ defined between a bottom of the panel engaging groove (8) and the pilot portion end face (7) is generally equal to maximum thickness of the metal panel. Further height ‘h’ defined between the seat face (10) of each corner post (9) and the pilot portion end face is generally equal to minimum thickness of the panel.

Abstract: A screw-holding belt (20) has a belt body (2) made from a plastics and having cutouts (8) that are formed at a pitch ‘P’ in and along side edges of the belt body so as to intermittently drive it. Passage holes (5) are formed at the same pitch as the cutouts in order to eject the screws (15), and have a diameter larger than their heads or washers. Screw-holding cylinders (3) are formed each in and coaxial with the central region passage hole (5), so that each screw's threaded leg is inserted into and held in the cylinder. Four stays (21) continue from the rim of upper opening (4) of each cylinder and extend outwards to the inner periphery of passage hole (5) in radial directions each intersecting the center line of belt body (2), so that the belt body can smoothly advance to eject the screws, without suffering from any trouble even if their heads or washers are of a large diameter.

Abstract: A self-drilling screw (20) for use in steel houses has: a leg (11) with opposite end regions and having a screw thread (18) formed by the rolling method, one of the leg end regions being formed as a drilling portion (17), the other end region continuing to a flathead (12) through a neck (13) disposed close to the flathead. A recess (14) formed in the flathead (12) can engage a wrenching bit of a screw driver, and the recess has torque-receiving vanes (15) extending generally in parallel with an axis of the screw. The neck (13) is a thickened portion of the leg (11) to have a diameter larger than a diameter of valleys of the thread (18) and smaller than its outer diameter. The neck (13) extends between the top of flathead (12) and the inner ends (15a) of vanes (15), with the recess (14) having a conical bottom (16) disposed in the leg, so that the thinned head of self-drilling screw withstands a strong torque for tightening it and also protects the driver bit from “caming-out”.

Abstract: A screw-holding belt (20) has a belt body (2) made from a plastics and having cutouts (8) that are formed at a pitch ‘P’ in and along side edges of the belt body so as to intermittently drive it. Passage holes (5) are formed at the same pitch as the cutouts in order to eject the screws (15), and have a diameter larger than their heads or washers. Screw-holding cylinders (3) are formed each in and coaxial with the central region passage hole (5), so that each screw's threaded leg is inserted into and held in the cylinder. Four stays (21) continue from the rim of upper opening (4) of each cylinder and extend outwards to the inner periphery of passage hole (5) in radial directions each intersecting the center line of belt body (2), so that the belt body can smoothly advance to eject the screws, without suffering from any trouble even if their heads or washers are of a large diameter.

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: An anchor (1) for hard stones has a female-threaded main part (2) formed of a stainless steel, a thinned cylindrical extension (3) formed of the same or a different stainless steel and preliminarily annealed, and an expander (4) substantially columnar in shape and harder than the thinned cylindrical extension (3). The extension holding the expander (4) has a distal tapered region (6) whose inner diameter gradually decreases towards a distal opening (5) of the extension. A proximal end of the extension is resistance welded to a distal end of the main part so as to be coaxial with each other. The expander can be struck towards the distal opening to be forced into engagement with the tapered region, causing a partial and plastic deformation of the extension.

Abstract: An elongate threaded fastener (50) for attaching the roofing panels (8) has a first part (20) and a second part (30), both made of a steel, and the first part (20) is composed of an elongate non-threaded shank (22) and a fastening rod portion (23) continuing from the shank and of a reduced diameter. The second part (30) is composed of an increased-diameter rod portion (35) and a head (36) formed at the proximal end of this portion. The first and second parts (20,30) are resistance welded together, before a boring means (24) such as a drill tip is formed on the distal end of the fastening rod portion (23). Then, both the fastening and increased-diameter rod portions (23,35) are rolled to form screw threads (23a,35a) respectively on them such that a method is provided to manufacture more efficiently at an improved productivity the threaded fastener (50) having the proximal threaded rod portion (35) whose diameter can be designed large enough.

Abstract: A self-fixing bolt 1 has a male-threaded body 2 and an annular barrel portion 3 having an upper region that continues from the lower end of the body. The barrel portion 3 has an outer periphery larger in diameter than the body 2, the barrel portion having a cylindrical opening 4 with a lower end to punch a hole in the metal panel 10 when driven to be attached to this panel. The bolt has a thrust-bearing shoulder 5 formed integral with the upper region of the barrel portion. Anti-rotation retentive lugs 9 protrude in a longitudinal direction from the outer periphery 8 of the barrel portion to be pointed outwards in a radial direction, each lug 9 being of a triangular or trapezoid cross section, so that the bolt is not accompanied by any oversized flange, thus rendered smaller in size and lighter in weight, and nevertheless surely protected from any undesired idle rotation relative to the panel when the its portion and the bolt form an assembly.