On Feb 18, 4:28*pm, "Steve Lusardi" wrote:
Tim,
If you heat the bits enough to change the color, you are ruining the temper
of the steel and defeating your purpose before you start. Buy a bench
grinder, quench often and be patient.
Steve

Very true for carbon steel. HSS doesn't anneal that easily and
quenching can cause cracks.

Jim Wilkins