5310-00-618-9972 (55367)
NSN 5310-00-618-9972 (NIIN 00-618-9972) is a flat washer in Federal Supply Class 5310, Nuts And Washers — a washer having a centrally located hole with a solid or laminated cross-section and two flat parallel bearing surfaces. Manufacturer part number 55367 (Northrop Grumman Systems Corporation, CAGE 26916).
Key specs: 25 to 32 rockwell c hardness; full characteristics table below. NIIN assigned January 1963; DEMIL A (none required); unit of issue EA (each), $4.53 gov standard price.