On Oct 2, 7:25*am, "Ed Huntress" wrote:
"Jim Wilkins" wrote in message
...
However, it's important to keep in mind what lapping will and will not do..
It can produce better roundness than grinding. But it does not improve
concentricity.
--
Ed Huntress

Filing and sanding can also degrade roundness and add a taper, but
they are quick and easy, all you need is a good "hand" or "pillar"
file. That's why I mentioned using the remaining tool marks as a
guide. You don't need to try to leave them, cut as close to size as
you can, filing shouldn't take off more than a few ten-thousandths and
sanding is barely measurable. At the hobbyist level a few remaining
fine marks don't harm a bearing surface. They may even help by
carrying oil.