[KevMoto]

Depends on how you thread I imagine.

Rigid tapping is always a hit or miss with Mach 3 in my opinion, but there are folks who do it. Those using a servo spindle should be able to reliably though.

Thread milling can be done with nearly any CNC mill as exact RPM is not critical.

Extension compression tapping should be doable with most mills that are reasonably close to RPM numbers and have decent torque at lower RPMs.

I do most of my tapping as a secondary operation on my drill press with a tapping head.

There is also the start and stop time for the spindle to consider.

I was thinking of external or internal threads over a longer distance, using the lathe, the way the auto-feed is already set up with the gears.