A screw (1), in particular a concrete screw, for being screwed into a drilled hole (20) comprises a core (2) with a pilot end (3), a lengthwise screw-in direction (5) and a central longitudinal axis (4); and a thread (7), which is designed in a single piece with the core (2) and which comprises a cutting thread (9), the cutting thread (9) extending from the pilot end (3) counter to the lengthwise screw-in direction (5) and having flanks (12, 13), which are substantially parallel to each other, a...

An element with a thread is created, in which both partial flanks enclose a negative angle with a plane extending perpendicular to the screw axis. Further, a screw or a hook for connecting to a rod, as used in particular in spinal column surgery, is created, wherein the inner thread of a holder, to which the rod is connected, and the associated thread of a nut comprise the thread according to the invention.

A screw which can be more quickly screwed into a work piece and has better chip-exhausting effect. The screw has a rod body and higher thread and lower thread formed on the rod body. On a conic section of the screw, a cutting thread with another guide angle larger than the guide angle of the lower thread directly extends from the lower thread. Accordingly, the lower thread of the screw has better cuffing, drilling and chip-exhausting function. Alternatively, the screw can have single thread or d...

A screw includes a rod-shaped portion, and a spiral-shaped thread winding around the rod-shaped portion. The rod-shaped portion has a straight portion, and a front end portion tapering towards a pointed front end. Several cutting trenches are formed on the rod-shaped portion for cutting bits off a workpiece with which when the screw is being screwed into the same. The tapering front end portion is provided with a notch, and cutting teeth are provided on that portion of the thread corresponding t...

A screw, particularly a wood screw present a combination of a threaded cylindric stem (10) merging, over an inversely frustoconical part (16) with an enlarged diameter cylindric portion (20) which is integral with an underside of a large diameter washer section (23) which, in turn is integral with a shallowly convex head portion (25). The invention is intended for wood screws usually in the range of about 6 mm and provides a reduced chance of injury by providing a smooth merging with the flat su...

A self-drilling screw (10) having a body (16) that includes a driving head (18) and aperture (20) at its one end and a self-drilling tap (22) at its other end. Intermediate the length of screw (10) a solid annular member (24) comprising a peripheral edge (31) separating annular surfaces (32, 33) is formed. A plurality of radially extending serrations or teeth (36) is formed on the one annular surface (32), in a circumferential pattern paralleling the turning motion of the screw (10) in its appli...

A screw adapted to be driven by an ordinary straight-bladed screwdriver, the head of the screw having a cylindrical socket formed in the top surface of the head thereof coaxially with the screw shank adapted to receive the driver blade therein, the wall of the socket preventing lateral slippage of the driver blade from the socket and permitting turning of the blade, portions of the wall being offset resiliently inwardly to inhibit turning of the blade, and so configurated that a partial turn of ...

A screw having a tool slot in the upper surface of its head, wherein the tool slot is defined by a plurality of circularly arched upright grooves and a plurality of flat upright wall portions, which are alternatively arranged around the border of the tool slot for permitting a hex wrench and a grooved wrench to be alternatively fitted into the tool slot and driven to turn the screw; the head is made of oval shape having smoothly curved side wall portions and flat side wall portions alternatively...

A screw and complementary screw driver for use in relatively inaccessible places where, with conventional tools, difficulty would be encountered in locating the screw on end of screw driver in axial alignment therewith. Screw driver has a generally V-shaped screw engaging means having a root portion extending from screw driver stem, and a transverse portion interconnecting root portion with an oblique portion, the oblique portion extending obliquely to transverse portion. Screw has bridge portio...

The screw is provided with a three-lobed thread crest, followed by a threaded portion with a three-lobed thread geometry, which passes into a threaded portion with a circular thread geometry. In all three threaded portions the flank angle of the thread is 60.degree. and the flank angle of the thread crests extending beyond the nominal diameter of the screw is 30.degree..