lately ive been turning a bunch of 4130/4140, i havent worked long on the lathe but my question is how do i get a better finish when turning it. my finish is always a cold finish. granted it test fine but looks bad. so do i turn it faster, slower? positive rake, negative? .03, .015 rad tool or what works best?
thanks
info: usually turning 400-600 sfm, 3000rpm max, .01 rough .005 finish, tried both .03 and .015 rad with neg rake
example part ive made: .3125 od, .25 id about 1 3/4 long out of 3/8 4130 bar stock