"CAMCOMPCO" wrote in
oups.com:

Hi all,

Is there a way I can get a mirror like finish on a turned piece of
metal? I know I can use 1000 grit and finer on a piece as it is
chucked and turning in a lather, but how about the bored hole? How
would I get a, say, 1/4" or 3/8" internal surface glass smooth? I am
thinking of some sort of expanding reamer that I could put a 1000 grit
wet/dry sheet around and insert it in the hole as it is turning...seems
like I would just bunch up the paper though ;-)

Anyone ever have to get something "barring" smooth internally....what
did ya use?

Thanks again gang....as always, any help is greatly appreciated


A burnishing tool is the usual way. Barring that, if it's a through hole
you can "ballize" the hole. In other words, drill and ream the hole
slightly undersize then press the appropriate size ball bearing ball
through the hole. You can also use emory wrapped on a wooden dowel to
polish the I.D. (put a slot on the end to help with the wrap) and then
follow up with a split lap and some lapping compund.


--

Dan