A hardware apparatus includes a washer/nut member comprising a disc-shaped base plate with a nut-shaped projection extending therefrom, wherein the nut-shaped projection includes a through passage to the disc-shaped base plate and the disc-shaped base plate includes a through opening aligned with the through passage. An insert is positionable within the through passage of the nut-shaped projection, the insert including a disc-shaped flange, a projection at one side of the flange, and a passage through the flange and the projection, wherein the projection is engageable in the through opening, wherein a perimeter shape of the projection is configured to cooperate with a perimeter shape of the through opening to prevent rotation of the insert relative to the washer/nut member.

A hardware apparatus includes a washer/nut member comprising a disc-shaped base plate with a nut-shaped projection extending therefrom, wherein the nut-shaped projection includes a through passage to the disc-shaped base plate and the disc-shaped base plate includes a through opening aligned with the through passage. An insert is positionable within the through passage of the nut-shaped projection, the insert including a disc-shaped flange, a projection at one side of the flange, and a passage through the flange and the projection, wherein the projection is engageable in the through opening, wherein a perimeter shape of the projection is configured to cooperate with a perimeter shape of the through opening to prevent rotation of the insert relative to the washer/nut member.

There is provided an implant having a slack prevention function by an eccentric fitting structure. An engaging shaft 53, which is decentered with a screw shaft 52, is provided at the end of an abutment screw 5, and is engaged with an engaging hole 45 provided in the bottom of a screw hole 44, into which an abutment screw 5 is screwed, and thus, the screw shaft 52 is inclined to and eccentric from the screw hole 44. Thereby, the screw shaft 52 comes to be strongly pressed partially in a circumferential direction toward the screw hole 44, so that internal stress in the horizontal direction is accumulated on the screw shaft 52. The screw 5 is threaded with maintaining prevailing torque caused by the internal stress, which enables the screw 5 to be fastened to the right position.

There is provided an implant having a slack prevention function by an eccentric fitting structure. An engaging shaft 53, which is decentered with a screw shaft 52, is provided at the end of an abutment screw 5, and is engaged with an engaging hole 45 provided in the bottom of a screw hole 44, into which an abutment screw 5 is screwed, and thus, the screw shaft 52 is inclined to and eccentric from the screw hole 44. Thereby, the screw shaft 52 comes to be strongly pressed partially in a circumferential direction toward the screw hole 44, so that internal stress in the horizontal direction is accumulated on the screw shaft 52. The screw 5 is threaded with maintaining prevailing torque caused by the internal stress, which enables the screw 5 to be fastened to the right position.

A fastener including a screw receiving element extending along a first axis and having a first end and a second end, the screw receiving element including a through hole extending through a thickness of the screw receiving element perpendicular to the first axis, the fastener further including a retention element arranged at the first end of the screw receiving element, wherein the retention element is plate-shaped and extends in a direction perpendicular to the first axis of the screw receiving element, and the retention element further includes a panel facing surface extending in a plane substantially perpendicular to the first axis of the screw receiving element, and side surfaces extending in planes substantially along the first axis of the screw receiving element.

A fastener including a screw receiving element extending along a first axis and having a first end and a second end, the screw receiving element including a through hole extending through a thickness of the screw receiving element perpendicular to the first axis, the fastener further including a retention element arranged at the first end of the screw receiving element, wherein the retention element is plate-shaped and extends in a direction perpendicular to the first axis of the screw receiving element, and the retention element further includes a panel facing surface extending in a plane substantially perpendicular to the first axis of the screw receiving element, and side surfaces extending in planes substantially along the first axis of the screw receiving element.

A nonloosening bolt may comprise a first bolt and a second bolt. The first bolt may have a bolt head, and the second bolt may have a threaded tip. Conversely, the first bolt may have a threaded tip, and the second bolt may have a bolt head. The first bolt may comprise an eccentric columnar portion having a small-diameter male-threaded portion at an outside circumference thereof. The second bolt may comprise a small-diameter female-threaded hole that threadedly engages with the small-diameter threaded portion. Threaded engagement between the small-diameter threaded portion and the small-diameter threaded hole may result in a constitution in which the central axes and pitches of the threaded portions at the outside circumferences of the first bolt and the second bolt are aligned. An eccentric frustoconical protrusion may be provided at the first bolt so as to fit within an eccentric frustoconical hole provided at the second bolt.

A nut cap assembly for securing an internal component to an external component includes a seal cap having a base and a shroud extending from the base. The base includes a mounting flange configured to be mounted to the internal component. The base includes an opening at a mounting end of the base configured to be mounted to the internal component. The base includes a seal groove surrounding the opening configured to receive a seal. The seal groove is open at the mounting end to interface the seal with the internal component. The shroud includes a nut pocket has a cap anti-rotation feature. The nut cap assembly includes a nut received in the nut pocket. The nut includes a threaded bore configured to threadably receive a threaded fastener used to secure the internal component to the external component. The nut includes a nut anti-rotation feature interfacing with the cap anti-rotation feature.

A bolt-nut (1) includes: a nut body (4) in a substantially cylindrical shape; plural nut divided bodies (4a); a cover body (5) in a substantially cylindrical shape for covering the nut body (4); a cover-side tapered portion formed on an inner wall of the cover body (5); a nut-side tapered portion (4a) formed such that an outer diameter of an outer wall of the nut body (4) is reduced toward one end portion thereof so as to correspond to the cover-side tapered portion; a spring (6) that is accommodated together with the nut body (4) in the cover body (5); and a nut (2) that includes a lid body (7) covering the other end portion of the cover body (5). A bolt screw as a ridge of the bolt and a nut screw as a ridge of the nut body (4) have unequal pitches that are different from each other.

A fastener includes a male member having a head and a threaded portion protruding from the head along a longitudinal axis, and a female member having a body portion and a tubular tightening portion extending from the body portion along the longitudinal axis. The tubular tightening portion includes a thread bore receiving the threaded portion of the male member and a plurality of teeth formed on an outer surface of the tubular tightening portion. Further, the male member includes at least one arm extending form the head along the longitudinal axis, and the at least one arm of the male member includes a projection protruding radially inward from the arm and engaging the teeth of the female member.