An assortment of flat-head socket cap screws from Hillman. Socket cap screws carry a recessed internal socket drive to add strength. They are commonly used on machine parts, manufacturing equipment, and other mechanical applications. Variants in this assortment come in 5/16"-24 and 3/8"-24 fine thread sizes. Full assortments of #45117 contain ten (10) refills comprised of Hillman item numbers #45118 - #45127.