Cobalt Drill Bits For Hardened Steel

I've come to use the Irwin TurboMax bits on thick stock. They work much better than the usual sheet metal bits and around here only cost about a dollar more.
 
I think I might have saved the $15-20 for a carbide tipped bit. I had a test piece and used a blowtorch to heat where I wanted to drill the hole (annealing it). It got to about 600 degrees F. The best part was that the vice acted as a heat sink protecting where the knife blade would be. That part only got to about 150. After I let it all cool I used the same cobalt drill bit that wouldn't go through before. This time is sailed right through almost as if it was mild steel. Hopefully this will work for when I actually try it on my knife. Thanks again for all the help!
 
Gentlemen, we have liftoff! I annealed where I wanted to drill using the torch. Then I used the cobalt bit and it went in like a hot knife through butter. Now I have two 1/4" holes drilled perfectly. I have learned a lot from researching in this forum and I plan to use it a lot in the future. Thanks!
 
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