An assortment of button-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 range from #0-80 to #4-40 in coarse & fine thread sizes. Full assortments of #45051 contain sixteen (16) refills comprised of Hillman item numbers #45052 - #45067.