I just ran across this FB post by Ken Lee:
I just found this old photo I made up on my tablet. Our stock lug nut is 21mm. Sometimes shops will use a 7/8" and mess up the stupid chrome jacket. When the jacket is distorted, the 21mm will either not fit over the nut or the nut will get stuck in the socket. When this happens, you can cut a slot in the top of the jacket, insert a big slotted screwdriver and with a sharp twist, crack it open to reveal the actual steel nut. The nut underneath is a 20mm, but who has one of those?! Not me! A 13/16" will work just fine.