On 06 Aug 2003 20:55:29 GMT, a (Dave Baker) wrote:

Wash your bloody mouth out son! UNC - Unified National Coarse - British through
and through. Nothing to do with yanks.

No, it's American. We adopted it during WW2, because it's always
easier to do whatever the Americans tell us, then claim we invented
it.

Up in Dad's big shed, we still have several ton of these things....
Not many are under 1" though.