An insert for forming an end connection in a uni-axial composite material, and an end connection comprising at least one insert, is disclosed. The insert comprises a sleeve which comprises a plurality of fibers having a multi-axial arrangement. At least a portion of the interior surface of the sleeve comprises a thread formation. A method of forming an end connection in a uni-axial composite material is also disclosed. The method comprises providing a sleeve comprising a plurality of fibers having a multi-axial arrangement and providing a thread formation on at least a portion of the interior surface of the sleeve. The sleeve is positioned and secured within the uni-axial composite material.

The present disclosure provides for a bone screw formed of continuous fibers, for example. The bone screw may include a first portion having a cylindrical shape and extending in a longitudinal direction from a first end to a second end, for example. In various embodiments, the first portion may include a thermoplastic material and/or be substantially formed of a thermoplastic material. In various embodiments, the bone screw may include a second portion coupled to the first portion and surrounding the first portion, at least partly, for example. In various embodiments, the second portion may include a plurality of layers, each layer comprising a continuous fiber material, for example. In various embodiments, the continuous fibers may be oriented longitudinally, diagonally, helically, radially, etc. In various embodiments, the second portion may define an exposed thread pattern and a leading tip.

A riser section includes two filament-reinforced tubulars and a coupling sleeve for connecting the two filament-reinforced tubulars. The coupling sleeve includes a screw thread at opposite ends for cooperating with a screw thread provided on sections of the filament-reinforced tubulars. The riser section includes two torque locks, wherein the torque locks are each mounted on one of the filament-reinforced tubulars, and are on opposite ends of the coupling sleeve. The torque locks are provided with coupling teeth extending in an axial direction. The coupling sleeve is at opposite ends provided with coupling teeth extending in the axial direction. When the tubulars are screwed into the coupling sleeve and the torque locks have been mounted to secure the rotational movement of the tubulars relative to the coupling sleeve, the coupling teeth of each of the torque locks engages the coupling teeth of the coupling sleeve such that they block rotation of the torque lock relative to the coupling sleeve and allow for movement of the torque lock relative to the coupling sleeve in the axial direction, and thus allow for elongation of the sections of the tubulars including the screw thread. The pitch of the screw thread of the tubulars increases in a direction away from the end of the tubular, and the pitch of the screw threads of the coupling sleeve increases in a direction towards the end of the coupling sleeve.