reply from Super John M.B.E.

[motorworks]

I am having trouble with a software problem...
so I send a note to Dr. John...
Cutting 1/2-13 threads with Mach....something goes a shiqt...
asked john and he puts me straight:

"It's the 1/2" x 13 pitch, it's a bastards size your lot should have stuck to 1/2" x 12 whitworth.
no ****ing sympathy for you.............

he's alive and well

eddie

[spope14]

I have a whole pile of 1/2-12 UNS taps and dies from the late 1970's. Still use them for my own personal stuff, hats to see tools go to waste.