5310-00-702-4281 (58675)
NSN 5310-00-702-4281 (NIIN 00-702-4281) 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 58675 (Cae USA Inc., CAGE 1PQF4).
Key specs: 83 to 16 rockwell m hardness; full characteristics table below. NIIN assigned January 1963; DEMIL A (none required).