On Fri, 14 Nov 2003 12:03:37 -0500, "surftom"
wrote:

How do I *accurately* (n.nnnn) measure very small hole diameters?

I can poke them with a numbered drill but that would only get me close by
"feel" and only if the hole was a standard size. e.g. measureing a .0431
hole is kind of hard with a vernier or mic

No real reason - enquiring minds just want to know

Tom

Gently enter a standard taper pin (available in a wide range of
sizes)into the hole. Mic the diameter where it stops or mic the large
end diameter and calculate the entry diameter from the taper distance
- 1/4" per foot for imperial taper pins, 1 in 50 for metric pins.

jim