5310-01-337-6053 (70188-104U)
NSN 5310-01-337-6053 (NIIN 01-337-6053) is a convex washer in Federal Supply Class 5310, Nuts And Washers — a washer which is round with a centrally located hole. Manufacturer part number 70188-104U (Sps Technologies, LLC, CAGE 56878); also referenced as K29646-104NF (Howmet Global Fastening Systems Inc); 942009-4 (Monadnock Company, The); BACW10CA104CVU (The Boeing Company).
Key specs: 52 to 56 rockwell c hardness; full characteristics table below. NIIN assigned April 1991; DEMIL A (none required); unit of issue EA (each), $0.73 gov standard price; ships at 0.05 lb / 0.0003 cu ft.