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 thrust screw assembly includes a thrust screw and two threading dies for working the thrust screw. The thrust screw includes a first shank, a second shank, an external thread, and a thrust member. Each of the threading dies is provided with an external thread forming section and a flat portion forming section. In a first molding process, the first shank is worked to form the thrust member with two wing-shaped stop pieces. In a second molding process, the second shank is processed by the external thread forming section of each of the two threading dies to form the external thread on the second shank, and the two wing-shaped stop pieces is processed by the flat portion forming section of each of the two threading dies to form two flat portions on the two wing-shaped stop pieces simultaneously.

A solar panel attachment assembly including a purlin bent into a U-shaped channel with a mounting wall, an upright wall and a cross piece attached to the upper edge. A solar panel having a frame with a lower horizontal wall forming a mounting surface and a vertical wall forming an outer surface. An inwardly directed channel formed on the upper edge of the vertical wall surrounds and fixedly engages the edges of solar sensors. Attachment bolts with a portion of the body being threaded and a tip portion of the body having a drill bit formed therein. The drill bit has an outer diameter smaller than an outer diameter of the bolt threads, and the attachment bolts are positioned to extend through the cross piece of the purlin and through the lower horizontal wall of the cross-section to hold the solar panel in abutting engagement with the purlin.

A structural screw usable in multiple different substrates/materials includes a head end, a shank and a tapered end, the head end including a tool engaging part, the head end located at a first end of the shank and the tapered end located at a second end of the shank. A thread is formed along the shank, wherein the thread begins on the tapered end, extends onto the shank and terminates at a first axial location along the shank that is spaced from the head end. The thread (i) is a multiple start thread formed by at least a first helical thread and a second helical thread and/or (ii) includes a thread angle of between fifteen degrees and thirty degrees. The screw may also include a reaming section with leading and trailing wedge sections and/or an asymmetric notch pattern along at least part of the thread edge.

A screw and method for the mounting of boards/planks, in particular fiber cement planks, on a support of wood. The screw comprises milling wings and a first thread between the milling wings and the tip, and a second, larger thread with smaller pitch between the milling wings and the screw head.

A screw includes a shank, a first thread, and a second thread. The shank includes a screw-in portion, a head portion, and a straight rod portion between the screw-in portion and the head portion. The first thread surrounds the shank spirally and includes an upper thread portion formed around the straight rod portion, a lower thread portion formed around the screw-in portion, and a middle thread portion continuously connected between the upper and lower thread portions. A plurality of serrate cutting teeth is provided on the middle thread portion of the first thread. The second thread is helically formed around the screw-in portion of the shank and includes a plurality of thread convolutions spaced from thread convolutions of the lower thread portion of the first thread. The screw can be quickly driven into articles to be joined without degradation of binding capacity between the screw and the articles.

Presently disclosed is a standoff fastener for use in a compound floor structure. The threaded fastener includes a threaded standoff portion designed to accept a nut which has a diameter larger than a head portion of the standoff fastener. The head portion is located centrally within the fastener in order to reduce a tendency of the fastener to pivot within a driver during the fastening process.

A building structure including a first building member and a second building member may be connected by a plurality of fasteners, each fastener having a head, a threaded portion having a through hardness of between HRB 70 and HRC 40, a thread-forming portion of at least HRC 50 hardness enabling the fastener to form threads in at least the second steel building member, and a fluted lead portion of at least HRC 50 hardness with a nominal diameter between 70 and 95% of major diameter, such that the fastener is capable of providing a ratio of strip torque to thread-forming torque of at least 3.0 and a ratio of strip torque to drive torque greater than 6.0 when the second steel building member having a thickness of 0.25 inch and the fluted lead portion having at least one diameter within nominal diameter between 80 and 98% of major diameter.

A fastener may include an elongated shank, a head at a distal end of the shank, and a drill point at a terminal end of the shank, which is opposite to the distal end. The fastener may include a primary thread starting at the drill point and extending along the shank towards the head. The fastener may include a secondary thread starting at the drill point, extending along the shank towards the head, and stopping in an axial direction before the primary thread ends. The secondary thread may be radially located 180 degrees from the primary thread. The drill point may include a plurality of radially extending cutting edges and one or more relieved flute portion extending along the surface of the drill point.

A fastener including a chisel point that pre-bores a hole in a work piece to prevent damage to the work piece as the fastener advances. The fastener can include a head, a shaft and a chisel brake point formed at an end of the shaft. The chisel brake point can include first and second opposing inclined surfaces disposed at an angle of about 80° to about 150° relative to one another. A thread can begin adjacent the chisel brake point and form an extension of an inclined surface and/or a chisel edge. The chisel brake point can scrape material from a work piece while pre-boring a hole. The material can be transferred to the thread, and subsequently fed up the thread, out of the pre-bored hole. The chisel brake point can also selectively retard advancement of the fastener into the work piece. Methods of installing the fastener also are provided.