"DoN. Nichols" wrote in message
...
snip----

Of course, the same could be said for any size drill bit, but it
gets rather insane to pilot drill for a 0.100" diameter drill bit. :-)


Not to be confused with the concept of double drilling holes to insure hole
size. It's poor practice to drill holes in one step when the diameter is
critical. Even when not stated, holes have a standard tolerance which is
easy to miss with a twist drill. By double drilling, starting roughly .015"
undersized, you have a much better chance of ending up with a hole of the
desired size. It usually take three steps to drill a proper hole. Center
drill (or spot drill), drill undersized, drill desired size. .

Harold