Carl wrote: (clip)chucking the rod at both ends in a lathe within a pipe to
maintain straightness and hand crank or use your back gearing to twist
(clip)
^^^^^^^^^^^^^
That comes very close to the method I described in an earlier post, using a
pipe-threading machine, and I expect it would work perfctly well. I imagine
that your lathe, with its gearing, has easily as much torque as my pipe
threader did.