5305-01-237-2136 (000991658-002)
NSN 5305-01-237-2136 (NIIN 01-237-2136) is a socket head cap screw in Federal Supply Class 5305, Screws — an externally threaded fastener whose threaded portion is of one nominal diameter. Manufacturer part number 000991658-002 (Zf Industrieantriebe Witten Gmbh, CAGE D9182); also referenced as 3M991N4-12 (Sps Technologies, LLC); NAS1352C4-12 (National Aerospace Standards); 023880003 ITEM 10 (Waukesha Bearings Corporation).
Key specs: 80 rockwell b minimum overall hardness; full characteristics table below. NIIN assigned July 1986; DEMIL A (none required); unit of issue PG (package), $17.06 gov standard price; ships at 0.014 lb / 0.0001 cu ft.