Oil Vs Water (Manual Machining Headache)

Sep 19, 2025 Last reply: 10 months ago 3 Replies

I typically apply cutting oil by hand, and water soluble by a flood blast from a pump. (more or less)



Whenever I see a video of somebody using one of those old smaller turret lathes I watch. Slowly I've been piecing together everything I need to know to set up a job on mine.



Recently I watched a video and the operator was using pumped flood oil. It wasn't the blast of nozzles I use with water soluble coolant on the CNC mills, but it was a solid continuous stream.



I typically don't use flood on the lathe because I don't like being soaked by coolant, but this was controlled and the oil did not seem to be slung off like a water based cutting fluid. The other reason I don't often use flood on the lathe is the coolant evaporates just sitting there. I use my bigger lathe mostly for repair work. I use manually applied cutting fluids on the big manual mill for the same reason. The coolant disappears, even though I do use it a lot more than the lathe for roughing mold blanks to size. Neither gets used for many production jobs.



I'd like to hear your experiences and observations. If oil stays on the work better, and it doesn't evaporate (not at the same rate as water anyway) it could be an answer for lathe work.



I'd not have a problem dumping several gallons of relatively expensive cutting oil into the lathes (after cleaning them out) if it would reduce some of the headaches of cutting fluid on those machines. They both have tanks and pumps in their respective base. Maybe not the mill I use it at speeds and feeds that sling chips yards (meters), not inches (centimeters).


I'd like to hear your experiences and observations. If oil stays on the work better, and it doesn't evaporate (not at the same rate as water anyway) it could be an answer for lathe work.

---------------------------------------

formatting link
My experience may not mean much to you since I'm not in high speed production. I machine dry or with a little brushed-on or needle oiler cutting or pipe threading oil, which sometimes gives a better finish, sometimes not, the machine tells me what it wants by sight, sound and feel. Only parting actually demands oil, tapping firmly requests it. Nothing I own is set up for flood cooling. Kerosene works well enough for me on aluminum. The best finish I've achieved was on annealed rock drill rod steel with dry diamond honed carbide.

The only times I use lube of any kind on the lathe is parting and threading , and both get oil based cutting fluid . I occasionally dribble a little ATF on the mill while facing aluminum .

ATF is actually a very good cutting fluid for aluminum. I used it in a flood setup on my Taig mill for a while.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required