On Mon, 30 Jul 2007 13:39:44 -0700, TC wrote:

This may be a dumb question, but is it easy to drill through iron?

I need to drill 2 x 3/16-inch holes through the cast iron cap of a 1-
inch black pipe. I've never drilled through anything tougher than
wood, so I don't know if that's a big deal or not. What kind of drill
bits should I buy? What drill speed should I use? Should I use a
lubricant? How many holes can I make with each bit? (I need a total of
8.) Since the surface isn't flat, do I have to worry about the bit
bending away from my target spot? How long can I expect each hole to
take?

I just finished step-drilling a 3/8" hole through a 1/4" thick cast
iron table of an old table saw. Centerpunch, started with a 3/16"
good quality bit, finished with a 3/8" bit. All done with a cordless
hand drill. (couldn't hold it up properly on the drill press).

Caveat: if the hard surface layer from casting is still present, use
a file to knock it off. Drilling through that layer is likely to ruin
the bit.

Best -- Terry