On Mon, 27 Jul 2009 20:58:02 -0500, cavelamb
wrote:

John R. Carroll wrote:
Karl Townsend wrote:
It depends on the material Karl not the rating as a bolt.
Carbon steel and Stainless are both avaliable in grade 8.
Its a steel bolt.

Then you'll be good with a HSS Split point drill at 40 SFM and oil for a
lubricant.
Keep a good bite on your drill but it won't work harden and peck often as
you refresh the cutting oil.



The real difficulty is breaking through the far side.
Snug up the Z axis clamp a little and pay attention.
LOL



Got a trick to keep from breaking bits on the back side?

Back up the workpiece with a bit of scrap steel or even aluminum. The
workpiece (and the backing beneath it) should be in a vise.