5310-01-059-5431 (SL61N-M12)
NSN 5310-01-059-5431 (NIIN 01-059-5431) is a round plain nut in Federal Supply Class 5310, Nuts And Washers — a nut, circular in shape, which may have wrenching facilities such as flats, holes, protrusions. Manufacturer part number SL61N-M12; also referenced as SL61N-M12 X 1 F (Sps Technologies LLC).
Key specs: 26 to 33 rockwell c hardness; full characteristics table below. NIIN assigned April 1978; DEMIL A (none required). Supersedes 5310-01-030-3823 (1991).