5310-00-208-2255 (404)
NSN 5310-00-208-2255 (NIIN 00-208-2255) is a hexagon self-locking nut in Federal Supply Class 5310, Nuts And Washers — a nut having a flat bottom and 6 sides. Manufacturer part number 404; also referenced as AN364-1414C (Aeronautical Standards Group Dept Of); 404 840 (Piper Industrial Manufacturing); MS20364-1414C (Military Standards).
NIIN assigned January 1963; DEMIL A (none required). Supersedes 5310-00-285-5643 (1963); related NSN 5310-00-942-5183.