A fastener includes a shank having a first end and a second end defining a length. The fastener includes a thread provided on the shank, the thread including a first region adjacent to the first end and a second region between the first region and a head at the second end, the thread includes a leading edge and a trailing edge, each edge forming an angle with a surface of the shank, the leading edge forming a non-normal angle with the surface of the shank and the trailing edge forming an angle about normal to the surface of the shank. The fastener may include an arcuate detent region in the shank between respective turns of the thread, the detent region having a length, the length decreasing from the first end toward the second end between the respective turns. The fastener may include a plurality of flutes positioned along a length of the shank.

A different-material fastener fastens together a first member and a second member formed from a material different from a material of the first member. The different-material fastener includes a rivet and a stud. The rivet includes a shank configured to be pressed into the first member, and a first head disposed at one end of the shank. The first head has a diameter larger than a diameter of the shank. The stud includes a shaft protruding from a center of an upper surface of the first head, and a second head that is disposed at an end of the shaft. The second head has a diameter larger than a diameter of the shaft and smaller than the diameter of the first head.

The present invention relates to attachment mean (1) for connecting plane components in dry construction, in particular for fixing two-dimensional construction material to a metallic substructure, having a shaft (2) on one end region of which a point (3) and on the other end region of which a head (4) are formed, a fine thread (5) being formed on the shaft (2) in order to increase extraction values of the attachment means (1), at least in regions, a number of grooves (6) being provided on the shaft (2) which extend substantially parallel to the central axis (X) of the shaft (2).

A self-penetrating thread forming and flow drilling fastener for thick materials with a generally cylindrical partially threaded shank, a drive system at the first end of the shank and a flow drilling tip at the second end of the shank. The flow drilling tip is sized larger than the minor diameter of the threaded shank but less than the major diameter to control installation torque enabling installation into thick materials with greatly reduced risk of torsional failure resultant from a decrease in torque. The flow drilling tip and threads may be a variety of shapes or thread types based on the substrate material the fastener is installed into.

A method produces a composite component from a first joining element and a second joining element by use of an adhesive and a flow drill screw. Before attaching the second joining element to the first joining element, a recess is made around the at least one screw position in which the respective flow drill screw penetrates the second joining element, in a joining surface of the second joining element.

A fastening structure includes: plural overlapping co-fastened members, a clearance hole being formed at at least one mating face of mutual mating faces of the plural co-fastened members, and a screw utilizing frictional heat to bore a hole and form a thread, passing through the clearance hole, and fastening the plural co-fastened members together.

A self-tapping screw includes a head portion, a lower side thereof configured with a screw rod, a front end thereof configured with a drill tail, a first thread segment formed on a front end of the screw rod above the drill tail, a second thread segment with at least two threads formed on a rear end of the screw rod immediately below the head portion, a crest angle of any one of the threads of the second screw segment being 1.15 to 1.2 times of a crest angle of any thread of the first thread segment, and a thread root diameter of the second thread segment increasing proportionally with the crest angle of the second thread segment. Whereby, the present invention provides a self-tapping screw capable of tight locking without idling.

A screw fastener comprising: an elongate shank (3) having a screw thread (9) extending along at least a substantial portion of the shank; a drive section (7) located at one end of the shank for allowing the screw fastener to be rotatably driven into one or more material layers; and a self-drilling or piercing point (5) at an opposing end thereof for forming a bore in said one or more material layers; wherein the drive section is shaped to minimise or avoid the need for countersinking of the formed bore.

A multipurpose screw is provided. The screw comprises: a head having a tool engaging formation, a self-drilling drill tip, and a shank extending between the head and the drill tip. The shank includes a threaded portion and an unthreaded portion. The threaded portion includes a major thread extending from the drill tip. The ratio between the major diameter of the major thread and the pitch of the major thread is from 1.2 to 2.4.

A wood screw includes a head, a shank axially extending from the head, a main thread extending helically around the shank in a tightening direction and having an outer diameter ranging from 3 to 16 mm, and a plurality of forward ribs extending spirally around the shank in a same direction as the main thread. The number of the forward ribs ranges from three to five. Each forward rib, in a cross section thereof, has a first outer edge facing the tightening direction, and a second outer edge facing opposite the tightening direction and having a length shorter than that of the first outer edge. Each forward rib has a height smaller than that of the main thread, and a lead angle greater than that of the main thread.