5340-00-016-6003 (586644)
NSN 5340-00-016-6003 (NIIN 00-016-6003) is a helical compression spring seat in Federal Supply Class 5340, Hardware, Commercial — a circular item, usually having a flat or grooved flange, boss(es), and/or counterbore, designed to accommodate the end of the spring. Manufacturer part number 586644 (Rtx Corporation, CAGE 77445).
Key specs: 35 to 40 rockwell c material hardness; full characteristics table below. NIIN assigned April 1967; DEMIL A (none required).