: Ran into a problem drilling cotter pin holes through two 1/2 bolts though.
: Made good progress on the first one then I think I melted/broke off the
: tip of the drill bit. Went back to the hardware store and came home with a
: cobalt bit. Couldn't get through it but started on the other side and was
: able to break through. Lucky me - the holes actually came together in a
: straight line.

: Then I started working on the second one and it started very easily but won't
: go any further. Don't know if the bit was dulled finishing up that other
: hole or I just got a super strong bolt. Very frustrating. Just ran back to
: a hardware store over lunch and the guy said that the titanium coated bit
: is stronger than the cobalt. So I'll give it a try, but does anyone have
: any suggestions about a better bit to use or what the problem might be?
: I've tried both my regular electric drill and my dremel, thinking a higher
: speed might help, but neither is doing a thing.

Patsy,

The cobalt bits should be fine. In addition to the oil, use a sharp drill and don't run a high speed. A dull drill or too high a speed will cause the material to harden, and the cutting rate will go way down.

Sam