I'm installing a disc brake kit and the bottom bolts that go through the spindles and into the steering arms have to be drilled from 7/16" out to 1/2". I bought some cobalt bits and was able to drill the spindle holes pretty easily. The steering arms are a whole other story. I've destroyed four expensive bits trying to drill these things. Come to think of it, I'm constantly destroying drill bits. Is there some trick to drilling steel without going through $100 worth of drill bits? Or is that just the way it is? I try to go slow, use some oil.... but no luck.
