Machine screws and nuts are used in conjunction with one another in order to fasten metal parts together securely. To ensure proper fit and quality of life, make sure to use machine screws with nuts of similar thread size and finish. Screws and nuts in this assortment all feature 3/8"-24 fine screw thread. Included screw variants range 3/4" to 3" in length. Full assortments of #46489 contain eight (8) refills comprised of Hillman item numbers #46490 - #46497.