DLMS™ Summary National Stock Number 1020-00-274-3291 National Stock Number (NSN) 1020-00-274-3291, or NIIN 002743291, (ring,piston) 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 no manufacturer part numbers associated to this NSN. This part number has not been procured by the US Government in over 5 years. 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 1020002743291 does not contain precious metals. This NSN is associated to Schedule B 9305913010: parts and accessories of military artillery weapons of 9301.11 or 9301.19. The Schedule B End Use is listed as tanks, artillery, missiles, rockets, guns and ammunition. NAICS classification category 332994: small arms, ordnance, and ordnance accessories manufacturing. This information was last updated on Oct 01, 2016.