A steel fastener having an elongate shank, an enlarged head formed at one end of the shank, and a generally pointed tip formed at the other end of the shank, the shank having a knurled portion formed with helical grooves defining helical ribs and with annular grooves defining annular rings, wherein the knurled portion extends up the shaft to adjacent an underside of the head.

A steel fastener having an elongate shank, an enlarged head formed at one end of the shank, and a generally pointed tip formed at the other end of the shank, the shank having a knurled portion formed with helical grooves defining helical ribs and with annular grooves defining annular rings, wherein the knurled portion extends up the shaft to adjacent an underside of the head.

A press-in retainer includes a retainer head having a collar and a seal disposed at least partially about the collar. A clip portion projects from the collar. The seal includes a main body engaging the collar and a sealing foot disposed entirely outboard from the collar. The sealing foot is configured to hinge about an intersection of the sealing foot and body portion while remaining entirely outboard from the main body. In a substantially flattened condition of the sealing foot, an angle between the sealing foot and a distal surface of the main body approaches a flat contiguous surface.

A press-in retainer includes a retainer head having a collar and a seal disposed at least partially about the collar. A clip portion projects from the collar. The seal includes a main body engaging the collar and a sealing foot disposed entirely outboard from the collar. The sealing foot is configured to hinge about an intersection of the sealing foot and body portion while remaining entirely outboard from the main body. In a substantially flattened condition of the sealing foot, an angle between the sealing foot and a distal surface of the main body approaches a flat contiguous surface.

A fastener comprising a polymer composition [composition (C)] comprising at least one polyaryletherketone polymer [(PAEK) polymer], and at least one nitride (NI) of an element having an electronegativity (ε) of from 1.3 to 2.5, as listed in <<Handbook of Chemistry and Physics>>, CRC Press, 64.sup.th edition, pages B-65 to B-158, based on the total weight of the composition (C).

A fastener comprising a polymer composition [composition (C)] comprising at least one polyaryletherketone polymer [(PAEK) polymer], and at least one nitride (NI) of an element having an electronegativity (ε) of from 1.3 to 2.5, as listed in <<Handbook of Chemistry and Physics>>, CRC Press, 64.sup.th edition, pages B-65 to B-158, based on the total weight of the composition (C).

Described herein is a retaining pin comprising a tubular outer shaft and a rotatable shaft disposed within the tubular outer shaft. The rotatable shaft is rotatably engaged with the tubular outer shaft. The rotatable shaft can comprise a locking protrusion fixed to an end of the rotatable shaft and that is operable to rotate with rotation of the rotatable shaft. An axis of the tubular outer shaft and an axis of the rotatable shaft are eccentric.

Described herein is a retaining pin comprising a tubular outer shaft and a rotatable shaft disposed within the tubular outer shaft. The rotatable shaft is rotatably engaged with the tubular outer shaft. The rotatable shaft can comprise a locking protrusion fixed to an end of the rotatable shaft and that is operable to rotate with rotation of the rotatable shaft. An axis of the tubular outer shaft and an axis of the rotatable shaft are eccentric.

A securing mechanism comprises a supporting column, an elastic piece, and a plurality of locking pieces. When the supporting column is inserted into a hole, at least one of the plurality of locking pieces is caught by or brought into pressure-contact with an outlet-side peripheral portion of the hole or an inner circumferential portion of the hole. The plurality of locking pieces form a plurality of arrays extending in a projection direction of the supporting column. The locking pieces included in each array of the plurality of arrays are aligned spaced apart from one another in the projection direction of the supporting column. The plurality of arrays comprise a first array and a second array; positions of the locking pieces in the first array are displaced from positions of the corresponding locking pieces in the second array in the projection direction of the supporting column.

The present disclosure relates a rivet body, including a rivet head and a rivet shank, composed of a different material than a mandrel used for insertion into a workpiece(s), the mandrel including a mandrel shaft and a mandrel cap. The rivet body receives the mandrel shaft, including the mandrel cap, through the rivet shank. The mandrel shaft is received by the installation tool, which rotates the rivet body, and the mandrel cap locally deforms workpieces(s) through friction riveting to install the rivet body. During the friction riveting, the fast-rotating rivet body is pushed into the workpiece(s) causing local deformation/melting where the mandrel cap contacts the workpiece(s). The mandrel cap creates a cavity which progresses through an upper surface and a lower surface of the workpiece(s).