5310-00-056-7819 (BL-2421)
5310-00-056-7819 is equivalent to manufacture part number BL-2421. It is a hexagon castellated plain nut and is classified under Federal Supply Class 5310 (5310 - Nuts and Washers), stocked for defense, aerospace, MRO, and industrial maintenance applications. This item is cataloged in the NATO supply system under 5310 - Nuts and Washers and is available through NSN-PARTS for U.S. government MRO, and commercial procurement.