On Jun 27, 5:08*pm, "Ed Huntress" wrote:
"Joseph Gwinn" wrote in message
...

When you get into really high-speed cutting, Joe, they often run dry -- or
with a 1/2-liter per 24 hour lean oil (vegetable) mist.
--
Ed Huntress

The Cincinnatti Milling Machine book that Lindsay used to sell (and I
can't find) contained reports on extensive cutting experiments that
seem to be the origin of accepted practice. IIRC their results were
considerably less definitive than the rules that developed, for
instance they found little difference between oiled and dry on cast
iron, and suggested dry mainly to minimize the mess. I've based my
practice of using a minimum of brushed-on oil on their results,
considering that I make one-off parts and can easily regrind a drill
or lathe bit afterwards.

jsw