I just partially rewired someone's garage. They had some NMB cable running through a piece of EMT that wasn't connected to anything else. I am thinking I need to bond this piece of pipe. (It goes overhead to another garage behind the one I rewired. Gotta love the maintenance man.) Anyway, I am hoping I can just put a ground clamp on that piece of pipe and hook it to a ground wire in the closest electrical box. (The garage is powered by one 15A multiwire circuit.) I remember reading something about having to bond both ends of the pipe but I have no idea whether that was just a discussion or if it is somewhere in the code book.