A resilient cotter pin that has longitudinal central portions that fit in the through hole of a related part. Shoulders connected to longitudinal portions abut the through hole and support curvilinear arms that terminate in an inwardly directed projections that engage a related castellated nut.

A resilient cotter pin that has longitudinal central portions that fit in the through hole of a related part. Shoulders connected to longitudinal portions abut the through hole and support curvilinear arms that terminate in an inwardly directed projections that engage a related castellated nut.

A castle nut has a groove around an exterior circumference thereof. An end plate has a through hole extending in a direction perpendicular to a longitudinal axis of a firearm. When a buffer tube is threaded onto a lower receiver of the firearm with the buffer tube traversing through the castle nut and the end plate, the castle nut can be screwed in a direction toward the lower receiver to fasten the end plate against the lower receiver. When the end plate is fastened against the lower receiver by the castle nut, the securing device can be screwed into the through hole of the end plate such that a portion of the securing device is engaged with the groove of the castle nut to prevent the castle nut to be loosened by being unscrewed in a direction away from the lower receiver.

The present invention includes a fastener comprising: a fastener body having a longitudinal axis and a first external male threaded portion, and two or more through-holes perpendicular to the longitudinal axis of the fastener body in the threaded portion.

The present invention includes a fastener comprising: a fastener body having a longitudinal axis and a first external male threaded portion, and two or more through-holes perpendicular to the longitudinal axis of the fastener body in the threaded portion.

A tie bolt retention assembly includes a retention ring configured to contact a tie bolt head of a tie bolt; a retention washer configured to be disposed between the tie bolt head and a wheel section of a wheel assembly; and a retainer configured to engage with the retention washer; wherein the retention washer and the retainer are configured to secure the retention ring to the tie bolt head.

A ceramic fastener assembly for high temperatures. One embodiment is a fastener assembly that includes a ceramic fastener configured to engage a hole of a structure. The ceramic fastener includes a head and a non-threaded shank including one or more indentations around its perimeter. The fastener assembly also includes a sleeve configured to slide over the non-threaded shank of the ceramic fastener. The sleeve includes a hollow cylindrical body, an exterior surface with threads, and an interior surface with one or more protrusions configured to mate with the one or more indentations of the non-threaded shank. The fastener assembly further includes a nut configured to engage the threads of the sleeve to tighten the one or more protrusions with the one or more indentations of the non-threaded shank. The fastener assembly also includes a thermal spacer configured to thermally isolate the nut and the sleeve from the structure.

A castle nut has a groove around an exterior circumference thereof. An end plate has a through hole extending in a direction perpendicular to a longitudinal axis of a firearm. When a buffer tube is threaded onto a lower receiver of the firearm with the buffer tube traversing through the castle nut and the end plate, the castle nut can be screwed in a direction toward the lower receiver to fasten the end plate against the lower receiver. When the end plate is fastened against the lower receiver by the castle nut, the securing device can be screwed into the through hole of the end plate such that a portion of the securing device is engaged with the groove of the castle nut to prevent the castle nut to be loosened by being unscrewed in a direction away from the lower receiver.

An anchoring assembly comprises a stud with an external elongate surface carrying a screw thread, and a through tunnel fabricated on the stud intersecting and perpendicular to a longitudinal axis of the stud; a construct comprising an eyelet enclosing an opening and a pair of holder members extending out from the eyelet; a nut having a sidewall defining an internally threaded passage, the nut carrying a pair of axially aligned and radially extending through holes on the sidewall, the through holes being adjustable to align with the through tunnel forming a continuous passage thereof; and a pivot pin fillable into the passage across the through holes and the through tunnel to lock the nut to the stud. The eyelet is configured to be rotatable around the longitudinal axis of the stud and the locked nut impedes the construct to move along longitudinal axis of the stud.

A threaded coupling is provided that comprises a first coupling member, comprising a cylindrical portion which is internally threaded around an axis of rotational symmetry of the cylindrical portion and comprises an open end that defines an opening having an annular rim; a second coupling member comprising an externally threaded portion and at least one key cavity; and a locking assembly. The locking assembly comprises a lock pin and a lock nut. The externally threaded portion is arranged to be received through the opening to be threadedly engaged with the internally threaded cylindrical portion to couple the first coupling member to the second coupling member. The rim comprises at least one projection that projects in a generally axial direction parallel to the axis of rotational symmetry of the cylindrical portion.