Torque disc

1. A torque disc comprising:

a fixing surface, the fixing surface defining an area of the torque disc for attachment to a fastener in use; and

at least one restraining element, with a substantially spherical or hemispherical shape, extending from the fixing surface so as to engage in use with at least one portion of the fastener to restrain rotational movement of the fastener during attachment to or detachment from the torque disc,

wherein the torque disc is a composite material torque disc comprising a polymer matrix embedded with a core structural fiber, wherein the core structural fiber repeatedly encircles the fixing surface to form a hub of increased thickness in the torque disc.

2. A torque disc according to claim 1 , wherein the fixing surface is shaped to define the at least one restraining element.

3. A torque disc according to claim 1 , wherein the at least one restraining element is a protrusion extending out of the fixing surface.

4. A torque disc according to claim 3 , wherein the protrusion is shaped to interference fit inside the at least one portion of the fastener.

5. A torque disc according to claim 1 , wherein the at least one restraining element is a depression extending into the fixing surface.

6. A torque disc according to claim 1 , wherein the fixing surface defines an opening, arranged adjacent to the at least one restraining element, for the passage of a portion of the fastener in use through the torque disc, towards the fixing surface or away from the fixing surface.

7. A torque disc according to claim 1 , wherein the hub surrounds the opening.

8. A torque disc assembly comprising:

a torque disc according to claim 1 ; and

a fastener comprising at least one second restraining element arranged to engage with the at least one restraining element extending from the fixing surface so as to restrain rotational movement of the fastener during attachment or detachment of the fastener to or from the torque disc.

9. A torque disc assembly according to claim 8 , wherein the fastener comprises a threaded bolt and a nut, the nut defining a threaded hole to screw-fit onto the threaded bolt.

10. A torque disc assembly according to claim 9 , wherein the nut comprises a bearing surface contacting the fixing surface of the torque disc and wherein the at least one second restraining element extends from the bearing surface of the nut.

11. A torque disc assembly according to claim 9 , wherein the fastener comprises an insert, the insert comprising an opening to house the nut and a bearing surface contacting the fixing surface of the torque disc, wherein the at least one second restraining element extends from the bearing surface of the insert.