In article ,
"Martin H. Eastburn" wrote:

Buy some solid carbide drills. They work just fine red hot.
Drill small holes and then work up - easier to work it that way.

I once drilled a 3/8" hole in the end of a large tap with a carbide
drill in my lathe. It was very hard but the carbide worked wonders, it
was a 1-flute straight drill.

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