Coolant or cutting oil for drilling 6Al4V titanium?

Drilling 4" long, 1/16" diameter holes in Ti. Only have a dozen parts to do so it's not high production. Using Dormer A 9401 & A977, cobalt, 130* split point drills. Have a good feed/speed/peck cycle.

Did a bunch of searching here and elsewhere and am confusing myself more than anything. Some recommend a cutting oil such as Moly-D and others an oil based cutting fluid. Even others a full synthetic tapping fluid.

Timet says "Chlorinated or sulfo-chlorinated oils and soluble-oil emulsions are satisfactory as cutting fluids". Does this mean cutting oils like Moly-D, TapMagic etc. as well as water soluble cutting oils like Rustlick and Hangsterfer's? I'm leaning towards a flood coolant for the long holes to keep things cool, would a full synthetic tapping fluid be better?

Go with the flood soluble oil. Cutting Ti produces a lot of heat.

A 4" deep 1/16" hole in Ti?!?!?!?

tdmidget said:

Go with the flood soluble oil. Cutting Ti produces a lot of heat.

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Higher than normal concentration to increase lubrication?

Rstewart said:

A 4" deep 1/16" hole in Ti?!?!?!?

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Yessir! Hope to be straight to 0.010"...

Dear Terry,

When machining Heat Resistant Super Alloys (HRSA), a great deal of cooling is needed to be really effective. Soluble oils are fine for this application, as well as a semi-synthetic coolant. If you are not limited by any approvals or restricted chemicals, I would suggest using a fluid which contains and EP additive such as Chlorinated Paraffin. If you cannot utilize Chlorine, than I would suggest looking into a fluid which is ester based.

If you would like to discuss any additional options, please email me at [email protected]

Best regards,
Brett Reynolds, CMFS
Sr. Applications Engineer
Blaser Swisslube Inc.

Thanks all for the input, decided to go with Rustlick Pro CF...

That is 64x depth to dia ratio.... I really don't see this coming out too well. Without through spindle coolant, how is this even gonna work?
I suspect we will be hearing more about this. Either way Good Luck

Rstewart said:

That is 64x depth to dia ratio.... I really don't see this coming out too well. Without through spindle coolant, how is this even gonna work?
I suspect we will be hearing more about this. Either way Good Luck

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Sounds crazy I know but I was able to do a couple parts manually and they come out well, took LOTS of patience to peck drill. Have added a Z axis to my lathe to better do the job: