On 8/29/2010 4:12 PM, Bob Engelhardt wrote:
Wes wrote:
The drilled hole using a conventional hole is the pilot. The flat
ground one guides on
the previous drilled hole and takes out the drill cusp.

That's just flattening the bottom of a blind hole, that's not
counterboring - where the counterbore is larger than the drill hole. Or
maybe that's called counterboring, too, even though it's a very special
case.

If the result is a hole with the position, dimensions, profile, and
finish that you want it doesn't really matter how you got there.