Im having a bit of trouble deciding on coolant for a new machine thats being set up strictly for drilling.
I am going to run strait oil through one of those crazy Mitsubishi drills that are .0745 diameters with 25:1 L/D ratio. And its coolant through at 1000psi in a Haas VM3. Very small holes.
I will be drilling 6061 but also some 360 brass and 303 stainless.
I am thinking of running Hangsterfers Missilelube XXL as I have had good experience with it in my VF2 and Mori lathe. It also has a rather low viscosity of 6 cSt @ 40C. It foamed badly when shaken in a bottle but that went way down after adding a drip of their anti-foam additive.
Also suggested was their synthetic NG Hardcut. It is double the viscosity but doesn’t feel oily.
Does anyone have experience running oil through small, long L/D drills?
Does anyone have cavitation issues in a high-pressure pump?
Any other comments or suggestions would be greatly appreciated.
Oh, and we use oil because the owner will only use oil. On that I have no say
I've used Hangsterfer's Hard Cut 5258 Light with good success in high temp alloys and stainless steels. Much better tool life than Missilelube in those materials. The Missilelube is a product made with vegetable-based EP additives, good for aluminums and other non-ferrous metals, not so good for tougher materials.
If you want the best I've ever used for all-around performance, look closely at Blaser's Blasocut Vascomill 22. It's a vegetable-based cutting oil good for all materials, but especially nice in titaniums, stainless steels, cobalt chrome, and other high-temp alloys. I cut mostly 303 stainless with it and it was great.