[Michael C Henry]

I work for the army and removing broken bolts ( grade 8)is an everyday thing Colbalt is usualy my preferance. A sharp bit is the answer and not a loot of speed.I talked the shop into investing in a Drill Doctor.When you loose your edge just dress it and it starts cutting. If you spin a dull bit it builds up heat and becomes softer than your work and that very spot to be drilled becomes work hardened and sometimes even a carbide bitt wont cut it. Sharp ,not too fast,the right pressure, and watch out when you go through. I also have a guide for drilling safety wire holes $30 at Jeggs or Summit. Tools make all the difference when used right.