Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

  Have you tried diamond-tipped drills?  Small ones are pretty cheap.
I have purchased them from Kingsley North inc. lapidary supplies.
The bits cut through agate which is really hard stuff but I've never tried
them on metal.  If it was soft metal they might clog but I think that
since your metal is very hard it might work.  Remember, use a water bath
of some sort for cooling while drilling!

Good Luck,
Wayne