5310-00-855-2089 (1103803)
NSN 5310-00-855-2089 (NIIN 00-855-2089) is a hexagon plain nut in Federal Supply Class 5310, Nuts And Washers — a nut, flat on top and bottom having 6 flat sides. Manufacturer part number 1103803 (Rolls-Royce Airlines, CAGE K0680); also referenced as 6863010 (Allison Transmission Inc).
Key specs: 24 to 34 rockwell c hardness; full characteristics table below. NIIN assigned October 1967; DEMIL A (none required); unit of issue EA (each), $0.32 gov standard price.