5310-01-172-2575 (42)
NSN 5310-01-172-2575 (NIIN 01-172-2575) is an extended washer self-locking nut in Federal Supply Class 5310, Nuts And Washers — a nut having 12 drive points, 24 sides, and an integral washer which extends beyond the points or periphery. Manufacturer part number 42; also referenced as 42 FLW-1612 (Zf Industrieantriebe Witten Gmbh); BH00450-1612 (Bristol Industries, LLC).
Key specs: 34 to 43 rockwell c hardness; full characteristics table below. NIIN assigned February 1984; DEMIL A (none required); unit of issue EA (each), $95.56 gov standard price; ships at 0.1984 lb / 0.0015 cu ft.