Vegetable oil as a cutting oil for machining?

[wasillashack]

If it works for you OK but it does tend to go gummy.
Machine oil comes in many grades and is cheap enough so experiment with them, my lathe has a coolant system so I use sulpherised cutting oil. when I use a squeeze bottle I dilute it with kerosene this does not seem to hurt the cutting oil and it evaporates over a long period of time so mixing with the lathes coolant is not a problem so I use it as a general spray over all machine parts as a rust inhibitor.

At Westinghouse Nuclear Reactor Division, we used Crisco for all tapping in various grades of stainless steel, it held up better than anything else we found.