National Stock Number
5310-01-031-8387
National Stock Number (NSN) 5310-01-031-8387, or NIIN 010318387, (washer,flat) was assigned December 2, 1976 in the Federal Logistics Information System (FLIS). This NIIN is Available for Manual Assignment. This NSN does not replace any other NSNs.
There are no manufacturer part numbers associated to this NSN.
This part number has not been procured by the US Government in over a year. There have been 6 contracts issued for this part number, with 6 awards given. There is minimal competition for this NSN. The US Government has awarded contracts to 5 different suppliers. The last contract numbers awarded were: SPE4A622P3541, SPE4A622P3541, SPM5E813V3251, SPM5E712M1018, SPM5A711M2165. The total value of the awarded contracts has been US$ 10,064.52.
This NSN is somewhat common among different platforms, belonging to 5 different weapons systems.
There has been a small amount of demand for this national stock number. The demand for this NSN originated from less than 5 countries. Based on a planned procurement review by the Primary Inventory Control Activity (PICA) on Jun 02, 2005, 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) 13393. [A WASHER HAVING A CENTRALLY LOCATED HOLE WITH A SOLID OR LAMINATED CROSS-SECTION AND TWO FLAT PARALLEL BEARING SURFACES. THE HOLE MUST BE 75 PERCENT OR LESS THAN THE LARGEST DIMENSION AND THE BEARING SURFACE FINISH IS GREATER THAN 32 MICROINCH (0.8 MICROMETER). THE THICKNESS CANNOT EXCEED 25 PERCENT OF THE LARGEST OUTSIDE DIMENSION. WHEN THE LARGEST OUTSIDE DIMENSION IS LESS THAN 1/4 INCH OR 6MM, THE THICKNESS MUST BE 0.006 INCHES (0.15MM) OR GREATER AND FOR ITEMS 1/4 INCH (6MM) OR LARGER, THE THICKNESS MUST BE 0.016 INCHES (0.4MM) OR GREATER. THE MAXIMUM TOLERANCE IS APPLIED TO DIMENSIONS AND USED AS A DETERMINING FACTOR. ITEMS WITH SEPARABLE LAMINATION USE SHIM. FOR ITEMS FABRICATED FROM CERAMIC OR ELECTRICALLY RATED MATERIALS BY SPECIFICATION OR INDUSTRY STANDARDS USE INSULATOR (1), WASHER. EXCLUDES:DISK, VALVE, GRAPHITE IMPREGNATED AND LUBRICATED ITEMS.]. This item does not have a nuclear hardened feature but does have other critical feature(s) 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 5310010318387 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 Jul 01, 2025.