RE: Source and size of TF screws, bolts & Taps

[Bullwinkle <yd3@nvc.net>]

I always thought that thread pitch was the number of threads for
a length, i.e. 1/4 by 28 means a thread pitch of 28 threads per
inch. And, thread angle was the angle formed between each thread,
hump ,or V?  If the thread angle is the 28, what is the angle
formed in the V called?  I have seen a diagram or chart somewhere
and the BSF and UNF used different angles between the V's.