Best way to machine ball screws?

[JAZZCNC]

I was about to start by grinding of the hard casing with a bench grinder, but I reckon my 15mm diameter rolled screws will still be hard at the required 12mm dia for the bearings.

Not necceserialy If chinese origin then think you'll find there only 3-4mm of hardening.?
I've machined a few, I use indexed tipped tooling and buy tips from cutwell tools designed for cutting hard materials. They easily deal with hardening, my lathe is a bit more robust than the myford but it's only a boxford AUD so not exactly heavy duty.!!

Maybe some body's got a bit of an offcut that you could practice on.? . . . Don't think I have but will have a dig about if you want to try.?

EDIT: Opp's sorry didn't read properly didn't see the 12mm dia,yes it will probably still be hard but the hard tips will still handle the hardening on chinese screws.!!