George McKay on 01302556406.
He has a free catalogue against a S.A.E. listing BSF, UNF, BSW, UNC and also metric.
The catalogue lists up to 1/2" but he has bigger - so if you want something bigger than 1/2", then phone him.
Send an SAE A5 for free catalogue:-
GFM
Bristol House,
11 Roman Road,
Benetthorpe,
Doncaster,
DN4 5HA
A nice guy!
Tony