"PrecisionMachinisT" wrote in message
...
snip-

Any chucking reamer has an inherent back taper designed and ground about
the
diameter....generally its ~.002 / inch--and as such, they certainly *do*
lose a bit of diameter *each and every* time that you re-sharpen them.


While chucking reamers do have taper as you suggest, it is much more gentle.
Typically, a small chucking reamer (3/8", for example) would have about a
half thou taper in it's entire flute length.

You can usually tell if a reamer has been reground by checking the shank,
between the flutes and the area used to grip the reamer. Taper for the
flutes is generally set there before grinding a reamer to resize it. That
way one can alter the size of a reamer by tenths with no risk of ruining its
size while making the proper setup. As I said, I've reground a large
number of reamers in my day, and that's the process I was taught to use by
my mentor, who had spent his life time in the grinding room.

Because chucking reamers cut on the chamfer, Dave is somewhat right in that
you can sharpen them time and again and not lose size, but you're limited by
the center hole on the cutting end. As you repeatedly sharpen them, you
run into it, so you have to lose the center hole---but by then you generally
are satisfied that the reamer cuts the desired size, so it's no big loss.

Harold