Patent ID: 8801348

Claim:
A blind fastener for clamping together two components through which, in use, the fastener extends, said fastener comprising: a sleeve having a first end which is radially expandable; a threaded fastener configured to extend through the sleeve; an expansion head threadedly mounted on the threaded fastener to engage with said first end of the sleeve whereby movement of the expansion head towards a second end of the sleeve forces the first end to expand; a collar configured to engage with the second end of the sleeve and having an aperture through which the threaded fastener extends, wherein the threaded fastener has a head formation for effecting rotation of the threaded fastener in an assembled condition in which the collar is positioned between the head portion and the sleeve, said second end of the sleeve and the collar define confronting surfaces and said confronting surfaces comprise inter-engaging formations which resist relative rotation of the sleeve and collar but permit their axial separation, and the inter-engaging formations in the confronting surfaces of the sleeve and collar comprise a depression in the surface of the collar.