Harold and Susan Vordos wrote in message
...

"Dave Baker" wrote in message
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Harold and Susan Vordos wrote in message
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"Philippe Gravelle" wrote in
message
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I can only assume the subject says it all.

The only way to repair rusted reamers is to regrind them to a
different
size--------unless one can be happy with a tool that doesn't cut well.
It's
not something that one can do without a cutter or precision grinder,
but
best done on a precision grinder. Even then, the results would be
questionable.

Harold

Got to disagree I'm afraid. As reamers only cut on the leading edge I
don't
find it makes much difference what condition the flutes are in provided
there are no high spots. I've got a selection of old reamers with rust
specks all over them which I get from the local second hand tool shop
for
a
quid or so each and they all cut fine and to their nominal size. A quick
lick down the flutes with an oilstone to remove any burrs is all any of
them
have needed to become perfectly serviceable. The leading edge can be
resharpened as often as you like without altering the size.
--
Dave Baker - Puma Race Engines (www.pumaracing.co.uk)

There's rust, and then there's rust. There was no information provided
so
I responded to the worst case scenario. Can't speak for you, but I've
ground (for size) and sharpened more than my share of reamers in my day
and
have a pretty good idea of what it takes to get one to cut size------and
not
seize in the hole, or tear it up due to chip welding.

I agree with your comments if the reamer has superficial rust. I totally

disagree if it has more. Notice I didn't say the reamers wouldn't
cut----I simply claim they cease to be a precision tool, such as reamers
are.

Sure, if the imperfections are bad enough then of course they'll have some
impact on performance but multi flute tooling is very tolerant of
imperfections compared to single point tooling. Even if one flute has a chip
or rust spot somewhere the chances are another flute is going to clean up
the job on its way past. It depends on the type of tolerances the operator
is trying to work to and even quality reamers have a fair tolerance on
cutting size anyway. Tolerance for the smallest reamer is about 3 or 4
tenths and over a thou for bigger ones. Yes you can buy very high precision
reamers, often carbide ones, that are made to closer tolerances than that
but it's unlikely to be of any concern to the average machinist.

As you say though the OP hasn't said what kind of reamers these are or what
he is hoping to do with them so it's all a bit academic at the moment.