I've noticed in a couple of the few ARFs I've bought that often the metric clevices are very loose on the provided threaded metric rod, but will not thread onto an American 2-56 threaded rod. As a result, except for a GP 40 Stick, I throw away the metric clevices and rods, and replace them with Dubro or Sullivan. I like the Sullivan locking clips. I also usually avoid using metal clevices to connect to the carburetor arm unless it's plastic.