1-1/8" sounds correct. I use black impact sockets six sided. OR have a 3/4 drive set witha big bar on it to break them loose. I have had to use heat to remove some real bad ones. Keep in mind, these have a 250lb. or so tork when installed and then rust on too. AT home, I usually stand on my bar to break them loose! One yard I got wheels from a **** , just cut the nuts/studs off, didn't even try to unbolt! I wanted some nuts too, darn! Those are huge Budd type, with 300-500lbs torque, those are fun! I've broken tools trying to get those off, and have blown them off with torch myself at times.
