This is a nickel plated steel hook with a base that is 48mm (1.89 inches) diameter. From the base of the hook to the tip of the hook is 57mm (2.238 inches) and the diameter of the screw-in hook is 6.9mm (just over 0.272 inches). The hook opening is 11.5mm (0.45 inches). This hook has been tested to hold more than 100 pounds on a 1/8 inch thick steel plate.