"Harold and Susan Vordos" wrote in message
...

When hole size is critical, or you just plain want things to work out as
if
you're a skilled craftsman, start your hole with a center drill, drill
undersized, then open the hole to the desired size.

Harold,

Do you find you have issues with drills being pulled into the work when
double drilling? Working in a tool shop, we have no need for holes within a
thou or two (either rough drilled or reamed only) so I don't have to do it
very often at all. When I do, I find the drill frequently pulls into the
hole making for a broken drill bit, spun part, or both. We have gear feeds
on our radials at work so it's not necessarily an issue for us, but HSM's
rarely have that luxury.

Regards,

Robin