On Thursday, June 4, 2015 at 2:49:56 PM UTC-5, Lloyd E. Sponenburgh wrote:
I can roughly measure a reground 3-flute or 5-flute cutter using my lathe
as a fixture, measuring the shank, then the diff to the cutting edges.

That works. But I don't own a v-mic in order to do it right. Is there
another 'standard strategy' for measuring odd-number-flutes' diameter?

I've been going through all my old texts, and they all show a v-micrometer
as the preferred method. I was hoping for some old 'shop lore' method.

Lloyd

Here's one: Roll the cutter on a flat surface one revolution and measure it.
Solve for diameter.