Hi, All:
I have a piece of SS tubing approx 11/16 Dia that I need to thread
externally. It is critical that the threads be coincentric with the bore and
it is physically impossible to put this assembly in a lathe (It's part of
something else that does NOT come apart. I have about 4.5" of tube sticking
out to work with and need to thread the first one inch (The end that's
sticking out into the air). The surface it enters is not perpendicular and
quite rough. I can't get my mind beyond using a die to cut the threads but am
stumped on how to achieve concentricity.

Any ideas appreciated.