A nail screw, in particular for connecting facade boards or terrace planks made of wood, especially real wood, has a shaft, a conical tip formed at the front end region of the shaft and a head formed at the rear end region of the shaft. A thread has a forward facing insertion flank and a rearward facing grip flank between the conical tip and the head. The thread is a double thread, wherein a grip flank angle (α) measured between the grip flank and a plane perpendicular to the longitudinal axis of the nail screw is between 25 and 35 degrees, more preferably between 28 and 32 degrees, most preferably 30 degrees. The conical tip has a tip angle (ε) between 80 and 120 degrees, more preferably between 90 and 110 degrees, most preferably of 80, 90 or 100 degrees.

A drywall screw for fastening a plasterboard panel to a metal support is provided, the screw having a head, a tip portion and an elongate shank, wherein the tip portion adjoins the shank, wherein the drywall screw has a widening element for widening the first borehole in the plasterboard panel to a first borehole diameter t and breaking off upon impinging the metal support, wherein the head exceeds the first borehole diameter t with a pressing-in volume V.sub.1, wherein the shank has a thread-free underhead portion which falls below the first borehole diameter t with a receiving volume V.sub.2 which is at least 80% of the pressing-in volume V.sub.1.

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.

The present invention provides a fastening element for increasing fixing stability, the fastening element having a drill part formed at the bottom tip of the lower end of a fixing piece so that a fixing groove can be easily formed by means of the drill part when the fixing groove is formed on a structure, wherein one side of the drill part is formed to be pointed and the other side thereof is formed to be blunt so that the fastening element is easily screw-fastened to the fixing groove of the structure and, simultaneously, can be prevented from being loosened by external vibration and the like. The present invention has a protruding part protruding downward from the lower surface of a flange, so that the protruding part is pressed and fixed to the upper surface of the structure so as to enable the fastening element to be more firmly fixed to the structure. In addition, a polygonal upper flange is formed on the upper surface of the flange, and thus a fastening part or the upper flange of the fixing piece is fastened using a wrench and the like, so that the fastening element can be easily fixed onto the structure.

A method is provided for producing a steel component assembly, wherein a steel component having a predetermined breaking point is provided and the predetermined breaking point of the steel component is punched through by way of a press-fit element in order to form an opening. Subsequently, the press-fit element is pressed into the opening of the steel component, and, at least in overlap with the press-fit element, a component is adhesively bonded to the steel component by an adhesive applied over an area. A friction-drilling hole is melted through the press-fit element, the steel component and the component by way of a friction-drilling element.

A quick fastening screw includes a head, a shank with spirally-disposed thread convolutions, and a drilling portion. Each thread convolution has at least three flank sections and at least three arc sections each formed between any two adjacent flank sections. Two ends of each arc section and the flank sections adjacent to the arc section are respectively intersected to thereby form two joints. Between the two joints is formed a curved cutting portion which forms a radian not more than a quarter of a maximum thread radius so that each curved cutting portion becomes sharp to cut quickly, speed up a screwing operation, decrease the friction between the thread convolutions and a workpiece, and reduce the resistance and torque. The non-circular thread convolutions also receive cut debris efficiently and prevent the cracking of the workpiece caused by the undue accumulation of the debris.

A fastening system for a metallic cellular shipping container floor includes a potted insert with a body disposed between a top flange at one end and a bottom flange at another end. The body defines a channel from the top flange leading towards the bottom flange and has a depth not exceeding a distance from the top flange to the bottom flange. The system also includes a hole formed in a panel of a metallic cellular shipping container floor with a depth identical to or greater than a distance from a top portion of the top flange to a bottom portion of the bottom flange. Finally, the system includes a self-tapping screw disposed within the channel of the potted insert, and including a threaded shaft with tip at a distal end of the shaft, and a screw head at a proximal end of the shaft.

In order to prevent wood fringes at the edge of a hole from a countersunk screw (1), the screw-head (2) is provided with a tapering underside and inclined milling-ribs (8) on the tapering underside. Each milling-rib (8) has a planar front-side (15) delimited by smoothly curved convex milling-edge (17) for milling the material during countersinking of the screw-head (2).

The present invention provides a fast chip removal reaming screw, including a screw head, a rod body extending from the screw head and a first thread arranged on the rod body. The rod body includes a rod body portion connected to the screw head, an reaming portion, and a pointed cone portion. The reaming portion includes first reaming blocks, second reaming blocks and third reaming blocks which are disposed in a helically staggered manner, and chip removal paths formed between the first reaming blocks, the second reaming blocks and the third reaming blocks. A first width of the chip removal path located between the first reaming blocks and a second width of the chip removal path located between the second reaming blocks are different, so that wood chips can be fast removed to reduce a stress between the screw and a wood workpiece.

A wood screw structure comprises a screw head section, a rod section, a first screw thread and a plurality of crushing rib units. The rod section is sequentially integrally formed from the screw head section and comprises a first rod portion connecting the screw head section, a second rod portion, a third rod portion, and a tapered portion extending and tapering outwardly from the third rod portion. The first screw thread is disposed spirally and is protruded on an outer peripheral surface of the tapered portion, the second rod portion and the third rod portion. The crushing rib units are disposed spirally and protruded around the outer peripheral surface of the third rod portion and the tapered portion, and each of the crushing rib units includes a plurality of crushers protrudingly disposed on a rib body. A first discharge gap is formed between the crushers.