Dudee,
This has come up many times over the past 50+ years. It's just not feasiable to do. You still have a problem with rigidity of the fixture. Its takes lots of power to push a 4 or 5 pitch threading insert into a thread having to bury it nearly .108" deep in it's final passes. Even if you went back to thread milling RSC's you still have to have a rigidt setup. Next would be the timing of the thread and the taper of the thread. By the time you invest money into servo drives and controller, your talking about a down payment for a CNC lathe before building the machine. Not trying to discourage the idea of doing it. Going back to the days of cutting RSC's on long small diameter drill string compoents, we used to have two to three floating roller rests set up to support the pipe of bar while cutting the joints. Maybe a another way to look at it. Use polyutherane rollers on the roller rests, your bars will turn with very little vibration. Ken
I wonder if "PK" is some sort of coating such as "Parkerizing"?
Sorry, I'm not of much help here,
Ken