"Martin Eastburn" wrote in message
...
I did some grinding on my lathe some years ago. The stone was
sitting
in a pool of oil - and I shook it 'dry'. Tool post grinder cut a
nice
clean finish. Small grain showing. The stone naturally shot the
oil
outward and got dry so when the other half of the work was ground
(it was in the jaws) - the measurement and even a fingernail ran
over the
'edge' between grinding - both smooth but the grain showing was
obvious.
The only difference was the oil that worked on the surface.

My take on the whole thing - not oil between but the working surface
isn't as hot with oil pouring over it - without it tends to tear due
to
melting temp on the very edge due to heat. It makes for a rougher
surface than when cooled with a flood.

As far as the blocks I always thought it was atomic friction. The
surface is so fine that atoms touch. Rough surface allows only few
to touch.

Martin


Do steel (free electrons) and ceramic (bound electrons) blocks wring
differently?
--jsw