My boring head needs a leadscrew and the plans call for 6/40. Well I don't have this size or dies for this thread. But the bigger issue is turning an existing socket head screw.the ones I have are hardened . I have to be able to turn one according to plans so I can't simply change the bolt, or make one since I need the socket for adjustment. Can they be annealed, with it being a leadscrew in a brass threading I would think I can get away with it not being hardened afterwards. Any help , tips?.?? And how do I make the screw come out to .001 adjustment. If plans call for 6/40 ,can I use one of bolts I have say a 1/4-20 and still be say .0005 or would it stay the same. Can I use any of the bolts pictured?