Clamp Knurler Repair

[Frank S]

jjr2001 you may be looking at this from the wrong perspective. instead of trying to drill and tap into the end use a pin wiht a large head then grind a flat so it cannot turn then hold it in with a dog ear from the side. the body of the clamp has a lot of meat on it you could drill and tap in the thicker part close enough to the head of the pin that a washer would hold it in place.
Just get you some drill rod or even a couple of old broken drill bits large enough to make the heads out of then heat them up and normalize or anneal them turn the pin then re harden them