I was milling some parts yesterday on the Hurco. Some steel parts. I
was using AlTin coated carbide mills. The parts looked ok, and the
chips looked good. Mostly blue with a few silver chips. The parts were
not getting excessively hot, but after a while I could see a dull glow
coming off the mill. That kind of bothered me so I setup and air blast.
That had the added benefit of eliminating chip recutting. The thing
is to get everything I anted the air blast had to use a modestly decent
volume of air. The parts actually looked better and mills never reached
that glow again, even with long cut times.

Is an air blast like that common for cutting steel? Remember I have
been CNC machining for more than a couple years now, but 99% of the
parts I make are aluminum. Years ago I used to come on this group and
pester you folks about cutting aluminum parts faster and faster and more
efficiently.

If an air blast is useful for that sort of thing, what can I do to use
the air more efficiently. I have dismissed vortex tubes out of hand. I
have made one, and I have a commercial one, and they both waste a lot
more air than any benefit they might provide. Heck, you get some
cooling affect as the air expands out of any nozzle. I was actually
thinking about things like a better nozzle design on the air blast to
get a predictable cone of air, and making a ball mount with a slip clamp
to hold the air nozzle so it can be directed to exactly surround the tip
of the mill with its cone of air.