National Stock Number
4310-00-131-2921
National Stock Number (NSN) 4310-00-131-2921, or NIIN 001312921, (ring,piston) was assigned January 1, 1961 in the Federal Logistics Information System (FLIS). This NIIN is Available for Manual Assignment. This NSN does not replace any other NSNs.
There are 4 manufacturer part numbers associated with this NSN. 4 of those part number(s) are considered obsolete. The manufacturer part numbers were originally supplied by 5 suppliers. Today, 3 suppliers are listed as Active suppliers for this NSN. Of the active suppliers, only one supplier is 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 unique to one weapons system.
Based on a planned procurement review by the Primary Inventory Control Activity (PICA) on Sep 20, 2008, this NSN's acquisition method was noted as: Acquire directly from the actual manufacturer, whether or not the prime contractor is the actual manufacturer. The annual buy value of this part falls below the screening threshold of $10,000 but it has been screened for known source(s). (NOTE: This code shall not be used when screening parts entering the inventory. It shall not be assigned in preference to or supersede any other AMSC.) Valid AMCs: 1, 2, 3, 4 and 5.
This NSN is assigned to Item Name Code (INC) 11459. [A CIRCULAR, SINGLE OR MULTIPIECE ITEM, METALLIC OR NONMETALLIC IN COMPOSITION, DESIGNED TO BE FITTED IN A CIRCUMFERENTIAL GROOVE IN A PISTON AND TO SPRING OUTWARD AGAINST THE CYLINDER WALL TO FUNCTION AS A SEAL OR WIPER. IT IS SUPPLIED IN VARIOUS CROSS-SECTIONAL SHAPES AND IS CUT THROUGH AT ONE POINT TO ALLOW FOR INSTALLATION IN THE PISTON RING GROOVE. IT MAY INCLUDE AN EXPANDER. EXCLUDES:PACKING, PREFORMED; RETAINER, OIL SEAL; RETAINER, PACKING; RING, RETAINING; RING WIPER; AND SEAL RING, METAL.]. 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 4310001312921 contains an unknown precious metal.
This NSN is associated to Schedule B 8414902095: parts nesoi, of compressors other than refrigerating and air conditioning compressors. The Schedule B End Use is listed as industrial engines. NAICS classification category 333912: air and gas compressor manufacturing.
This information was last updated on Jul 01, 2025.