I heard 1000psi with through tool can make a big difference in high temp alloys, but I never got to try it myself. I only have 145psi.
Thing is, many coolants will just foam at these pressures.
I have a through tool parting holder/blade but I never even used it yet, shouldn't have bought it in the first place. 300psi+ would probably be better for that anyhow.
Thanks guys, that is exactly what I was looking for. I am only running flood and wash down pumps right now. Currently I route boring bars and indexable drills if they have coolant passages. Even with the low pressure it seams to help.
I am happy to hear some are reporting gains with moderate pressure and not full 1000psi+ systems only. I don’t have a desire to go to a setup like that right now but was considering a booster pump.
For clarity, I was referring to all the external through coolant holders, such as parting blades, external threading, and general turning.
High pressure coolant is almost always desirable. In regards to if it is worth the hassle...that depends on if improved tool life is the goal. If better tool life is needed, then high pressure coolant is the way to go.