National Stock Number (NSN) 4730-00-375-6403, or NIIN 003756403, (locknut,tube fitting) was assigned March 16, 1974 in the Federal Logistics Information System (FLIS). This NIIN is Available for Manual Assignment. This NSN replaces 2 stock numbers: 4730013606104, 4730006146473.
There are 7 manufacturer part numbers associated with this NSN. 3 of those part number(s) are considered obsolete. The manufacturer part numbers were originally supplied by 3 suppliers. Today, 3 suppliers are listed as Active suppliers for this NSN. Of the active suppliers, there are no suppliers that are deemed design controlled or valid supply parts. ISO Group has several sources of supply for this NSN.
This part number has not been procured by the US Government in over 5 years, with the most recent procurement date of Apr 23, 2019. There have been 7 contracts issued for this part number, with 26 awards given. There is minimal competition for this NSN. The US Government has awarded contracts to 4 different suppliers. The last contract numbers awarded were: SPE7L119F716F, SPE7M318V3702, SPE7MC18V2910, SPE7M517V6568, SPE7M917V0964. The total value of the awarded contracts has been US$ 3,092.31.
This NSN is very common among different weapons systems, belonging to 66 different platforms.
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 Apr 02, 2006, 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) 17645. [AN ITEM WITH INTERNAL MACHINE THREADS DESIGNED TO FIT THE EXTERNAL MACHINE THREADS OF A TUBE FITTING. IT HAS FLAT FACES, ONE OF WHICH HAS A COUNTERBORED RECESS TO ACCOMMODATE PACKING, PACKING OR SEALING RING(S), GASKET(S), AND THE LIKE. THE ITEM, WHEN INSTALLED, PROVIDES A METHOD OF LOCKING AND SEALING THE CONNECTION. SEE ALSO LOCKNUT, PIPE; NUT (1), TUBE COUPLING AND NUT (1), PLAIN, HEXAGON.]. 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 4730003756403 does not contain precious metals.
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.