On Mon, 12 Dec 2005 18:32:16 -0500, Bob Chilcoat wrote:

These aren't cast iron any more;
they're apparently some sort of powdered metal. Hard -- high-speed tool
bits just rolled over and died. Fortunately, I had some carbide bits that
worked fine, but this stuff doesn't produce a nice curly chip.

Cast iron never produces a curly chip. However, you should
be able to cut it with HSS.