"Ignoramus13544" wrote in message
...
Still kind of chicken about running a high speed spindle (a Bosch
router) without coolant. So my question is, do people use coolant at,
say, 10k RPM? 20k? I would say the OD of the spindle nut is 1 inch.

The super fast machines I have seen on You Tube all appear to use moderately
high volume flood coolant. There are plenty of people who claim they dry
cut at 10-24K, but cutter life suffers. Also sticking happens more often if
you try to get a little aggressive. I dry cut a lot, but if I care about
the finish of the part I stand there with a can of WD in my hand (aluminum
only).