Abstract: A novel threaded fastener is provided having an elongated shank portion with a first end and a second end opposed to the first end, and a helical thread in the form of a continuous helical ridge that is arranged on an external surface of the shank portion. The helical thread includes an asymmetrical threaded portion that has a progressively increasing axial displacement of a pressure flank of the helical thread between the first end and the second end of the shank portion, and a progressively decreasing axial displacement of a non-pressure flank of the helical thread between the first end and the second end of the shank portion. When assembled, the novel threaded fastener has a clamping force distribution that is evenly distributed on the helical threads along its axis in the direction of force transmission reducing the risk of self-loosening and increasing fatigue resistance.

Abstract: A fastener and a system, apparatus, and method for monitoring a fastener are described. The fastener includes a head portion, a shank portion, a transponder, and a compression spring, wherein the head portion includes a mounting portion, and wherein the transponder is disposed in the mounting portion of the head portion. The transponder is arranged to monitor the shank portion, and includes an ultrasonic sensor and a signal processing circuit. The ultrasonic sensor is affixed to a transducer hosting surface, and is urged against the transducer hosting surface by placement of the printed circuit board in the head portion with the compression spring intervening therebetween. The ultrasonic sensor communicates with the signal processing circuit via the compression spring. The signal processing circuit captures a signal from the ultrasonic sensor and transforms the signal into a parameter corresponding to a tensile force being exerted by the fastener.

Abstract: Screws are provided which have a longitudinal axis and include a threaded shank and a head wherein a socket is formed to be engaged by a wrench and having a pluri-lobed outer profile comprising a series of lobes circumferentially offset and separated by a series of circumferentially offset protrusions of the head. Each protrusion is delimited by two flanks and a front length joining the radially inner ends of the flanks and is convex and symmetrical with respect to a center axis radially oriented with respect to the longitudinal axis. The front length is formed by a center face and two inclined side faces each of which joins the radially inner end of the respective flank with a respective end of the center face, which is oriented orthogonally with respect to the center axis of the protrusion. Pluri-lobed wrenches adapted for use with such screws are also provided.

Abstract: Screws are provided which have a longitudinal axis and include a threaded shank and a head wherein a socket is formed to be engaged by a wrench and having a pluri-lobed outer profile comprising a series of lobes circumferentially offset and separated by a series of circumferentially offset protrusions of the head. Each protrusion is delimited by two flanks and a front length joining the radially inner ends of the flanks and is convex and symmetrical with respect to a center axis radially oriented with respect to the longitudinal axis. The front length is formed by a center face and two inclined side faces each of which joins the radially inner end of the respective flank with a respective end of the center face, which is oriented orthogonally with respect to the center axis of the protrusion. Pluri-lobed wrenches adapted for use with such screws are also provided.

Abstract: Screw elements are provided which include a shank having a thread and a head connected to the shank, the head having a tool engagement portion which comprises six corner domes arranged evenly distributed in the peripheral direction of the head and comprising respective flanks, by which the head can be brought into positive cooperation with a hexagon socket of a tool for tightening of the screw element, wherein respective recesses are arranged peripherally between the corner domes, and wherein the flanks of the corner domes are respectively provided at least partially with a radius.

Abstract: Screw elements are provided which include a shank having a thread and a head connected to the shank, the head having a tool engagement portion which comprises six corner domes arranged evenly distributed in the peripheral direction of the head and comprising respective flanks, by which the head can be brought into positive cooperation with a hexagon socket of a tool for tightening of the screw element, wherein respective recesses are arranged peripherally between the corner domes, and wherein the flanks of the corner domes are respectively provided at least partially with a radius.