If you have not tried it yet, RIGID makes a cutting oil which I have found to be really good stuff, no matter what metal I have used it on.  Rigid sells both a light and a dark cutting oil (fluid), if you want to experiment give the DARK cutting oil a try.  I don't use flood type coolant for my machining, both lathe and mill, and have used about every non-flooding type coolant/cutting oil made, and I really like the dark Rigid.  (Mike Shaffer)