5310-01-107-0031 (D5213)
NSN 5310-01-107-0031 (NIIN 01-107-0031) 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 D5213 (Katsuma Optical Co. Ltd, CAGE S4024).
NIIN assigned January 1981; DEMIL A (none required); ESD/EMI-sensitive; unit of issue EA (each), $0.55 gov standard price.