National Stock Number
5331-00-256-0201
National Stock Number (NSN) 5331-00-256-0201, or NIIN 002560201, (o-ring) was assigned January 27, 1987 in the Federal Logistics Information System (FLIS). This NIIN is Available for Manual Assignment. This NSN replaces 4 stock numbers: 5330004513513, 5330001943731, 5330002314105, 5330000546874.
There are 16 manufacturer part numbers associated with this NSN. 5 of those part number(s) are considered obsolete. The manufacturer part numbers were originally supplied by 7 suppliers. Today, 6 suppliers are listed as Active suppliers for this NSN. Of the active suppliers, only one supplier is 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.
This NSN is unique to one weapons system.
There has been very little demand for this national stock number. The demand for this NSN originated from less than 5 countries.
This NSN is assigned to Item Name Code (INC) 47946. [A NONMETALLIC CIRCULAR ITEM WITH AN APERATURE, HAVING A SOLID ROUND CROSS-SECTION. THEY ARE USED PRIMARILY FOR SEALING. FOR ITEMS WITH OTHER THAN ROUND CROSS SECTION, SEE PACKING,PREFORMED. FOR NONCIRCULAR ITEMS WITH A ROUND CROSS-SECTION, SEE SEAL,NONMETALLIC ROUND SECTION AND RUBBER,ROUND SECTION.]. 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 5331002560201 does not contain precious metals.
This information was last updated on Jul 01, 2026.