5310-01-098-1553 (SM-B-595971-1)
NSN 5310-01-098-1553 (NIIN 01-098-1553) is a lock washer in Federal Supply Class 5310, Nuts And Washers — a washer, usually round, with a centrally-located hole. Manufacturer part number SM-B-595971-1 (Us Army Communications & Electronics, CAGE 80063).
NIIN assigned July 1980; DEMIL A (none required).