Some years back, when I was running drain diggers, (track hoes to you Americans,) I'd lose a tooth off the bucket. The teeth were fixed to the stumps on the bucket with a locking pin. Sometimes it would be quite some time before I got around to replacing them, and the stump would get a bit worn, which meant I had to build it up with weld.
I had a brass (or copper, I can't remember which,) rod the exact same diameter as the hole for the locking pin which I would drive into the hole, weld around it, and knock it out again.
Instant perfectly sized hole for the pin, no drilling needed.