-
Bolt resembles an M5 but not the standard M5 thread, possibly finer
#10-32 UNF, 3/16×32TPI BSC, 3/16×32TPI BSF-Whitworth, 2BA
The first should only be found on US manufactured product, the others are candidates if the product is very old and British. An actual fine thread ISO M5 is the least likely, and once you go down that rabbit hole you're into a choice of almost any thread pitch according to the predilections of the engineer who specified it.
gbj_tester-
Thank you for the reply.
It is a BBB aluminium seat post that, I believe, was standard on this
'Team C' carbon Boardman, so shouldn't be 'very old'.I'm currently trying to emerge from the rabbit hole of near-Ruislip bike shops.
The least useful answer so far, inevitably is from the Ruislip High Street Specialized Concept store where I was told that they didn't have anything 'that looks like that'.
('That' being the other intact bolt).
I asked whether they had any bolts that could give the same function, but of course not.
And, of course, they do not stock any 31.6mm diameter seat posts.
mespilus
Another broken saddle clamp bolt.
This time it isn't so easily replaceable.
Bolt resembles an M5 but not the standard M5 thread, possibly finer.
It has bamboozled Orbital Fasteners of Rickmansworth.