National Stock Number
5310-00-021-8440
National Stock Number (NSN) 5310-00-021-8440, or NIIN 000218440, (nut,plain,hexagon) was assigned January 1, 1963 in the Federal Logistics Information System (FLIS). This NIIN is Available for Manual Assignment. This NSN does not replace any other NSNs.
There are 7 manufacturer part numbers associated with this NSN. 4 of those part number(s) are considered obsolete. The manufacturer part numbers were originally supplied by 8 suppliers. Today, 5 suppliers are listed as Active suppliers for this NSN. Of the active suppliers, 3 suppliers are deemed design controlled or valid supply parts.
This part number has not been procured by the US Government in over 5 years.
This NSN is assigned to Item Name Code (INC) 01857. [A NUT, FLAT ON TOP AND BOTTOM HAVING 6 FLAT SIDES. FOR ITEMS WHICH HAVE INTERNAL TAPERED OR STRAIGHT (PARALLEL) PIPE THREADS, SPECIFIC ELECTRICAL CONDUIT SIZE DESIGNATION, AND WHICH WHEN INSTALLED, PROVIDE A METHOD OF TIGHTENING TO LOCK THE CONNECTION, SEE LOCKNUT, ELECTRICAL CONDUIT. SEE ALSO LOCKNUT, TUBE FITTING. FOR ITEMS HAVING A THICKNESS (OR HEIGHT) EXCEEDING TWO TIMES THE WIDTH ACROSS THE FLATS, USE POST, ELECTRICAL-MECHANICAL EQUIPMENT. (WHEN HEIGHT OR THICKNESS AND/OR WIDTH ACROSS THE FLATS IS DESIGNATED AS A TOLERANCE DIMENSION, THE MAXIMUM DIMENSION WILL BE USED TO DETERMINE COMPLIANCE.)]. This item does not have a nuclear hardened feature or any other critical feature such as tolerance, fit restriction or application. There is no data in the HMIRS and the NSN is in an FSC not generally suspected of containing hazardous materials. NSN 5310000218440 contains an unknown precious metal.
This NSN is associated to Schedule B 7318160000: nuts of iron or steel. The Schedule B End Use is listed as finished metal shapes. NAICS classification category 332722: bolt, nut, screw, rivet, and washer manufacturing.
This information was last updated on Aug 01, 2025.