You should really indicate how the 1/2" is derived so people from other parts of the world (Canada) don't print this and then realize it's an entirely different fit. You see, I have hundreds of hex nuts that I keep organize for the work that I do. 1/4", 7/16", 1/2", 9/16", you name it. We measure the 1/2" from flat to flat. You probably measure the diameter of the hole. So my 1/2" nuts were WAY smaller than the openings in the spinner.