Socket Shoulder Screws are screws that have an unthreaded shoulder below the head to act as a fulcrum for a lever pivoted on it. Variants included in this assortment range 10mm thru 50mm in length and come in M6 and M8 diameters. Full assortments of #33764 contain thirteen (13) refills comprised of Hillman item numbers #33765 - #33777.