I don't know what the pros use, but I keep a oiler full of 30W by the
drill press for drilling metals. It must work because I haven't broken
a bit yet.

Thanks for your quick reply! I'm sure that's ideal, but I'd really
like to keep the DP table clean for use with wood. I know I can't
have it both ways, so I suppose I just need another DP dedicated for
metal...
Interesting to hear the HF bits are working for you - maybe I'll get
another set and just try to run them cooler. At their prices, I can
get the bulk packs of 1/8" and 3/16" bits and call them disposable.
Thanks,
Andy