"Dave Baker" wrote in message
...
....
Wash your bloody mouth out son! UNC - Unified National Coarse - British
through
and through. Nothing to do with yanks.

It is American Standard Coarse under a different name. Following
compatibility problems during WW2, Britain and the USA agreed to adopt a
unified thread system (UNC and UNF). However, as most of the hardware was
being built in the USA, what that actually meant was that Britain would
adopt the US system. Of course, they did not replace Whitworth and BSF, they
merely added to the range of choice available.

Colin Bignell