A method of transporting liquid petroleum gas (LPG) comprising coupling reverse thread fittings of a first tank to reverse thread fittings of a second tank, the first tank storing the LPG; and allowing the LPG to flow from the first tank to the second tank through the reverse thread fittings of the first tank and the reverse thread fittings of the second tank.

A relative rotation prevention structure for preventing relative rotation of a screw having a threaded section with respect to a counterpart member, the relative rotation prevention structure being equipped with: a counterpart-side displacement section formed in advance on the counterpart member and capable of displacement in the axial direction or the radial direction; and a screw-side deformation-capable section that is formed on the screw and deforms when pressed into the counterpart-side deformation section by means of fastening force and, due to that deformation, produces a screw-side displacement section that is displaced in the axial direction or the radial direction.

A screw fastener particularly adapted to improve retention while minimizing mushrooming in fibrous workpieces. A single-threaded lower portion neighbours the pointed tip of the screw and a dual-threaded upper portion neighbours the screw head. The upper portion has a first upper thread that spirals in an opposite direction to the singular lower thread, and a second upper thread that spirals in a same direction as the singular lower thread. The lower thread includes a plurality of thread turns that share a same major thread diameter while axially spanning multiple areas of the lower portion of the shaft that vary in diameter, including a bulged area, a reduced upper area of lesser shaft diameter than the bulged area at a location between the bulged area and the head, and a downwardly tapered lower area at which the diameter of the shaft narrows from the bulged area toward the pointed tip.

The invention relates to an apparatus for compensating tolerances between two components to be connected to one another, comprising a threaded element fastenable to a first component; a threaded bolt that has a first threaded section, which is in a first threaded engagement with the threaded element, a bolt collar and a second threaded section; and a threaded nut which can be brought into a second threaded engagement with the second threaded section, wherein the first threaded engagement and the second threaded engagement are formed in opposite senses; and wherein a friction locking or a form fit between the threaded bolt and the threaded nut can be produced by the threaded nut such that the threaded bolt is movable relative to the threaded element when the threaded nut is screwed onto the second threaded section.

A three-piece locking fastener including an interiorly threaded intermediate component open at opposite ends. A first screw having a first exterior thread pattern rotationally inter-engages with the interior threads of the intermediate component when installed through a first selected one of the opposite ends, the first screw having a hollow shaft exhibiting a further plurality of interior threads matching a direction of the first thread pattern. A second screw has a second exterior thread pattern opposite the first pattern and, upon being installed within the other selected one of the opposite ends, rotationally inter-engages the interior threads of the first screw, so that loosening of either of the first and second screws being prevented by their counter-threaded orientation.

A self-drilling screw includes a shank and at least one thread. The shank includes a self-drilling portion, a head portion spaced from the self-drilling portion along a longitudinal axis, and a straight rod portion between the self-drilling portion and the head portion. The thread is spirally formed on the straight rod portion and includes a plurality of thread convolutions. Each thread convolution is provided with three to eight recesses spaced apart circumferentially, and a screw thread portion is formed between two adjacent recesses. The recess features a recess length circumferentially, and the screw thread portion features a screw thread length circumferentially. The screw thread length is 25% to 200% of the recess length. The self-drilling screw can be driven into articles to be fastened quickly without loss of binding forces between the self-drilling screw and the articles.

A fastener bolt for clamping an electric wire includes a bolt part and a nut part. The bolt part has a head section, a thread section, and a shearing section connecting the head section and the thread section. The nut part is screwed onto the thread section. The shearing section is configured to break if a predetermined fastening torque is exceeded. The thread section is hollow and has a predetermined tensile breaking strength.

A hybrid metal plastic shear fastener bolt. The bolt includes a metal body having a first end and an opposing second end including a head and including a threaded shaft extending from the first end towards the second end along a longitudinal bolt axis. The bolt also includes a plastic torque head formed on the metal body configured to shear away from the metal body at a predetermined torque.

The present invention provides a structure for omitting washers to reduce the number of parts, and keeping the fitting of two members fastened together even when the washers are omitted. The structure includes: a first member having a first screw hole; a second member facing the first member, having a second screw hole larger than the first screw hole, and threaded in a direction opposite to the first screw hole; and a fastener. The fastener includes, along a longitudinal direction: a first screw section having a diameter corresponding to the first screw hole; a second screw section between the first member and the second member, having a diameter corresponding to the second screw hole, and threaded in a direction opposite to the first screw section; a neck at least partially located in the second screw hole; and a head larger in the longitudinal direction than the second screw hole.

A self-drilling screw includes a shank and at least one thread. The shank includes a self-drilling portion, a head portion spaced from the self-drilling portion along a longitudinal axis, and a straight rod portion between the self-drilling portion and the head portion. The thread is spirally formed on the straight rod portion and includes a plurality of thread convolutions. Each thread convolution is provided with three to eight recesses spaced apart circumferentially, and a screw thread portion is formed between two adjacent recesses. The recess features a recess length circumferentially, and the screw thread portion features a screw thread length circumferentially. The screw thread length is 25% to 200% of the recess length. The self-drilling screw can be driven into articles to be fastened quickly without loss of binding forces between the self-drilling screw and the articles.