National Stock Number
5310-00-499-3451
National Stock Number (NSN) 5310-00-499-3451, or NIIN 004993451, (washer,recessed) was assigned July 9, 1971 in the Federal Logistics Information System (FLIS). This NIIN is Available for Manual Assignment. This NSN does not replace any other NSNs.
There are 2 manufacturer part numbers associated with this NSN. None of the associated part number(s) are considered obsolete. The manufacturer part numbers were originally supplied by one supplier. Today, one supplier is listed as an Active supplier for this NSN. Of the active suppliers, there are no suppliers that 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 somewhat common among different platforms, belonging to 2 different weapons systems.
Based on a planned procurement review by the Primary Inventory Control Activity (PICA) on Jan 02, 2020, this NSN's acquisition method was noted as: Suitable for Competitive Acquisition. (Potential sources shall include dealers/distributors.) The Government has unlimited rights to the technical data, and the data package is complete. Valid AMCs: 1 and 2.
This NSN is assigned to Item Name Code (INC) 15933. [A WASHER OF ANY PERIPHERAL SHAPE HAVING A CENTRALLY LOCATED HOLE. BOTH BEARING SURFACES ARE PARALLEL AND FLAT, BUT ONE OR BOTH OF THE BEARING SURFACES MUST BE BROKEN BY A COUNTERBORE, COUNTERSINK, OR SIMILARLY SHAPED RECESS. THE THICKNESS MUST NOT EXCEED 25 PER CENT OF THE OUTSIDE DIAMETER OR THE LARGEST OUTSIDE DIMENSION. THE MAXIMUM LIMIT OF THE TOLERANCE OR RANGE APPLIED TO THE THICKNESS AND/OR LARGEST OUTSIDE DIMENSION MUST BE USED TO DETERMINE COMPLIANCE. EXCLUDES:WASHER, CONCAVE, RETAINER, PACKING, AND THRUST TYPE WASHERS. SEE ALSO SPACER, SLEEVE; AND SPACER, STEPPED.]. 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 5310004993451 contains an unknown precious metal.
This NSN is associated to Schedule B 7318220000: washers other than lock washers, 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.