No, they don't...

Sometimes solid posts were fitted with an external steel clamp, secured by bolts, that supported the two hinge pins. Victorian and later, I would guess, when that metal became cheaper and the skies of industrial cities were black with soot.

A likely supposition is that many or most of the stone fence or gate-posts on Orkney were originally megaliths. Everyone will draw the line at a different place, "this one is" and "this one isn't". The line I draw (in the sand) is whether I can discern the mark of a hardened steel chisel.

Anyone in the mood to purge sites could rifle through the ones TomBo posted around Stanhope way. The prose blinded us to his dubious site posts, I would suggest.