"Joseph Gwinn" wrote in message
...

Haven't tried it in steel and/or for large holes yet.


If I had to bet money, I'd say you're not feeding fast enough (pushing hard
enough). You should be able to countersink a 1/2" hole in steel at 500 RPM
with some practice.

You have to feed *hard* into the material (you'll need a good chuck as most
countersinks have pretty hard shanks) and retract quickly when you're at the
desired depth - no dilly-dallying at the bottom or throughout the cut.

Your idea about the lube is good. Countersinks are easy to burn and hard to
sharpen.

HTH.

Regards,

Robin