The tread is propitiatory
.276 X 40
if we just have to make this thread we take a 1/4 X 40 tap and run it through( hole is now .026 to small .016 on each side of hole.
find a wire that will almost fit in one of the flutes. back the tap out , slide wire in & tap again. Keep doing this with larger wires or two wires and sneak up on your shaft. This will work for one of, more than that make a tap.
This tip will also work on dies that cut a little large
Well that's all from the peanut gallery for now
George from Conyers Ga.
Edited because I got my figures wrong. I am old enough to make mistakes not Bads