wrote in message
...
If you are going to use the reamer idea can you make your own
reamer?
Then you can get the correct twist along with the correct diameter.
Of
course you may be able to get a reamer with a twist that works. I
have
ordered several straight flute reamers in custom sizes and they can
also be bought in increments of .0001 for diameters less than .500
from catalogs. But I don't know if spiral fluted reamers are sold
the
same way.
Eric

The price of entry to make precise spiral (helical) tooling is a
Universal Dividing Head geared to the milling machine table feed.
http://www.shars.com/products/view/3..._Dividing_Head

jsw