"Fdmorrison" wrote in message
...
"Ed Huntress"

Yes, although it's pretty rare. Ground surfaces on machine tool ways are
best used with pressure oil systems. When you don't have oil pressure, it
is
possible, with an exceptional grinding job, to get high friction.

The cure used in most machine tools is to "frost" the way surfaces, which
is
a sort of after-the fact scraping job, usually done with a power scraper
to
produce a decorative surface effect. You want it to be very shallow and
you
aren't scraping to a standard here. You're just trying to reduce the
bearing
area and leave some low areas (by millionths, not by tenths) to hold oil
and
to reduce the contact area.

Final scraping called "frosting," or "flaking" is used for hand scraping
of
ways for decoration (allegedly to hold oil), but would you want to use it
after
final grinding (other than for decoration)?

Yeah, that's how it was used a half-century ago. Real top-quality
hand-scraping jobs, like on Moores, weren't finished with frosting. BTW,
"flaking" was a term usually applied to hand-scraping of little points;
"frosting" usually was reserved for the more decorate, half-moon or other
patterns.

Even back in the '40s, it usually was done by power after grinding, on
mass-produced lathes and mills.

Whether it was purely decorative or not depended on the manufacturer and how
they did it.


If the surfaces here related "stuck" together dry (as Jo blocks) on
wringing,
that would be one thing, but that's not the case so far related.
FM

I won't try to analyze it, but my understanding is that it's simple adhesion
from too much area with too-thin a layer of oil between the surfaces. The
tribologists here can argue that one out. g

Ed Huntress