In article ,
"Dave Plowman (News)" wrote:

In article ,
Smitty Two wrote:
We're fairly used to UNF and UNC in the UK as they were much used on
cars before metric came in - but only really in the larger sizes. For
small stuff Lucas ;-) stuck to BA.


Oh yeah, I keep forgetting that you used to be in this mess with us.


But I still see AF and AC taps and dies around - are the two versions
still used? I realise there's not a vast difference - only basically
thread profile.

Terms with which I'm not familiar...

American Fine and American Course.

If those are predecessors to UNF and UNC, I don't think anyone's using
them anymore... The only other thread standard that we have that I know
about is the pipe thread, NPT.