Don, I've been known to use boxes with 1/2" K-Os and a romex connector(C-500). What is the next guy going to do with just a 1/2" K-O ? You can't make it idiot proof, maybe idiot resistant, but not idiot proof. This past winter we did a custom home with all steel boxes as per spec. When we went to trim out we discovered several boxes did not have the threaded ground screw hole. Just a dimple with GND stamped next to it. We drilled and tapped these boxes because the GC didn't think too much of our alternate plan of ripping the defective boxes out of the finished walls. My drilled and tapped holes weren't listed but they were made with the proper size drill bit and threaded with a tap and were identical to the other factory drilled/tapped holes in the box.
