5310-00-711-2145 (NAS1291C4)
NSN 5310-00-711-2145 (NIIN 00-711-2145) is a hexago extended washer plain nut in Federal Supply Class 5310, Nuts And Washers — a nut having 6 flat sides and an integral washer which extends beyond the flats or periphery. Manufacturer part number NAS1291C4 (National Aerospace Standards, CAGE 80205).
NIIN assigned January 1963; DEMIL A (none required). Supersedes 5310-00-836-3877 (1967); related NSN 5310-00-844-4872.