In article , "DoN. Nichols" wrote:
[...]
Unibit (step drill) leaves fewer and larger chips. Easier to
clean up.

I think that's the way I'm going to go. Thanks to all who suggested this.
[...]
The hole size sounds like it may be for a pilot light to remind
you the fan in the hood is on, or perhaps an industrial switch to
control the fan.

No, it's for a rocker switch to control a solenoid gas valve for our gas
cooktop. My inlaws live with us; MIL has some form of senile dementia, and
can't possibly be trusted with a gas stove. So we've been shutting off the gas
to the kitchen whenever we leave the house, but that's a PITA because the
shutoff is in the basement. I plan on putting a 24V transformer and solenoid
gas valve in the cabinet under the cooktop, and the switch in the range hood.
Even if she sees the switch and figures out what it's for (vanishingly
unlikely), she can't reach it anyway: due to shoulder problems, she can't
reach anything above her own eye level. Planned location for the switch is
above *mine*, and I'm 6" taller than she is.