I read this over at practicalmachinist.
Sounds like a good application for a Cole drill. It isn't a good idea, and unsafe as hell, but somtimes in an emergency a friend of a friend's uncle once removed and twice arested would heat a carbon steel twist drill to the critical temperature and quench in mercury. That thing would go through some pretty hard stuff! None of us would ever resort to using mercury but once upon a time it was a common method for this sort of thing. The Rivett 608 lathe spindle was hardened in mercury acording to the sales brochure.
I've never heard of this before. Is there something to this?
Wes