What would be my best bet for getting a relatively small quantity
(current requirement is 100 pieces) of machine screws (a couple of
sizes, like 6-32) made from 0.25" dia. metal rod. The material (Nb) is
soft like copper and generally nasty to machine. I'd like a Torx or
similar head so it's not as easy to screw up as a slot.

Ideas? Real screw-making machines - heading and thread forming- look
like a bit much for the purpose (thousands of pounds and many HP).