In article ,
Smitty Two wrote:
UNC is a coarse thread. UNF is a fine thread. UNEF is an extra fine
thread. 2-56, 4-40, 6-32, 8-32, and 10-32 are common, but many others
are prevalent as well, including the "odd" numbers, e.g. 3-48.

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.

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.

--
*'Progress' and 'Change' are not synonyms.

Dave Plowman London SW
To e-mail, change noise into sound.