Partly Threaded has an unthreaded area just below The top after which has partial threading along the rest of the physique. The component that's not threaded is known as the grip length. Imperial or inch thread sizes of flange bolts are specified by diameter and threads for every inch. Diameter https://josuetmcsh.ampedpages.com/helping-the-others-realize-the-advantages-of-custom-nut-56160148