Reply by trainwreck

My bit fits perfectly into the screw, and it is a new bit, but it’s cheap, I think—it was a gift from my father. The screws are 8×2 1/2 and coarsely threaded. They says they’re steel, but I’m pretty sure they’re plated with something. Actually, as I look at them more closely, it looks like I can use a No. 2 square bit with them, so maybe I’ll just try that and report back!