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.