A flooring screw comprises a screw head, a screw shank connected with the screw head, and a cone connected with screw shank. The screw shank includes a first shank section connected with the screw head, a second shank section connected with the cone, a first thread formed on the first shank section, a second thread extended from the cone to the second shank section and running helically along a direction opposite the direction of the first thread, and a third shank section between the first shank section and the second shank section. The third shank section includes a plurality of peaks protruding outward radially and a plurality of troughs formed between the peaks and recessed radially with respect to the peaks. The peaks and the troughs form an unsmooth surface on the third shank section.

The invention relates to a screw (10) including a head (12), a shaft (14), and a thread (16), with the thread (16) having at least two different thread sections (18, 20), with an external diameter D.sub.Gn of a thread section (18) near the head being smaller than an external diameter D.sub.Gf of a thread section (20) distant from the head and greater than an external diameter D.sub.Sf of the shaft (14) in the area of the thread section (20) distant from the head. According to the invention it is provided that the thread (16) extends up to the bottom of the head (12). The invention further relates to a fastening arrangement (24), the use thereof, and a method.

An integral nail/disk structure that eliminates the need of having any exposed nails associated with a shingled roof having a color matching body member integrally formed with a roofing nail. Another embodiment including a fastener such as a nail or screw having an enlarged head and an associated gasket member for fastening sheet metal to a roof structure. The gasket member has a sealant on both of its top and bottom surfaces so as to adhere both to the underside of the enlarged head portion of the nail or screw, and to the sheet metal to create a waterproof seal. Still another embodiment includes an enlarged cap member associated with a gasket member attached to its underside portion wherein the cap/gasket member can be attached over a fastener hole in a roof, or over a faulty roofing nail or screw in lieu of caulking techniques usually used to cure leaks where the faulty fastener attaches sheet metal to a roofing structure.

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 wall anchor for use in a cavity wall includes an elongate body having a driven end portion and a driving end portion. The driven end portion is adapted to be threadedly mounted on the inner wythe of the cavity wall. The elongate body includes a barrel portion adjacent the driven end portion. A first end of the barrel portion is adapted to abut the inner wythe of the cavity wall when installed. A thermal coating is disposed on the first end of the barrel portion. The thermal coating is configured and arranged to reduce thermal transfer in the cavity wall between the elongate body and the inner wythe when installed.

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 screw and anchor assembly include a male fastener and a female anchor. The male fastener only has threads or half-circular fins on half of the surface area. The other half is just like a regular cylinder. The female anchor only has threads or half-circular fins on half of the inner surface area. The other half is just like the inner wall of a regular cylinder. The user may push the male fastener into the female anchor, so the half-circular fins on the male fastener engages with the half-circular fins inside the female anchor and locks the male fastener to the female anchor. When the user needs to remove the male fastener, simply turns the male fastener 180 degrees and disengages the half-circular fins on the male fastener from the half-circular fins on the female anchor, then pull the male fastener from the female anchor.

A sheet metal screw includes one or more of a tapered self-drilling tip, an asymmetric thread angle and/or a trilobular thread edge profile.

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.