On Sun, 12 Jan 2014 07:17:29 -0600, Mark Storkamp
wrote:

In article s.com,
Kay wrote:

replying to anoldfart2, Kay wrote:
anoldfart2 wrote:

What do i use to drill a hole in steel door for the knob?
I got a hole saw, but the steel (tin) will destroy the teeth on it.
I know the inside of the door is wood, but the outer covering is
metal. The only way I can see is to drill about 50 small holes around
the needed circle size, but that seems like a pain.
Any suggestions?



I went through my mastercraft bimetal hole saw on my steel door
Then a 15$ one from princess auto then the most expensive one I could find
21$ and still all I get it a but of sparks, some smoke, and my paint
around the hole is
turning brown. I thought I got a good quality hole saw but they aren't
working. The center
Drill went through like butter but the hole saw seems to be just buffing
up the door(lol, jk). I spent
about 15 min trying, any other suggestions?

You want to keep the speed of the saw to around 50SFM. for a 1" hole saw
that would be around 200RPM. Too fast and you'll see sparks, smoke, and
burning paint.
And for a 2" diameter hole, that translates to closer to 60RPM -
meaning a half inch VARIABLE SPEED drill, running close to the low end
of it's range.