I remember back in the day pounding anything in that was somewhat oversize sledge hammer and it was fine... well I found studs that had a knurl .006" more than the .005" interference fit that the original studs had, stuck the whole deal on my press and carefully, carefully, and BANG and then this:



I found that a 14mm drill opened them up to .006" interference fit, and again, it cracked, but no big bang. The next size up drill bit that I could find, 9/16", gives something like a .001" interference fit... those went in easy but I'm afraid they won't be tight enough for the studs not to come loose long term.

I suspect that newer brake rotor castings are just cast out of brittle junk compared to old ones, but I can't spend all my time trying to track down old castings. I'm also not excited about trying to find a proper-sized (whatever that is?) reamer since cutting these rotors down into hubs wrecked carbide inserts (I was using dedicated carbide tooling that I snagged off a brake lathe and even that used roughly 2 carbide inserts per hub) and when I tried to use a file to break the sharp edges destroyed the teeth on the file.

 

No one? Has anyone had this happen to them?