National Stock Number
4520-01-656-1991
National Stock Number (NSN) 4520-01-656-1991, or NIIN 016561991, (pipe,air conditioning-heating) was assigned June 21, 2016 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 unique to one weapons system.
Based on a planned procurement review by the Primary Inventory Control Activity (PICA) on Jun 29, 2017, this NSN's acquisition method was noted as: Not established. Not established.
This NSN is assigned to Item Name Code (INC) 15681. [A SHAPED PRODUCT OF SHEET METAL; ROUND, RECTANGULAR, OR SQUARE IN CROSS-SECTIONAL SHAPE. IT IS UNIFORM THROUGHOUT ITS LENGTH. USED TO CONDUCT AIR OR GAS FUMES FROM ONE AREA TO ANOTHER.]. 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 4520016561991 does not contain precious metals.
This NSN is associated to Schedule B 8415909000: parts, nesoi, of air conditioning machines. The Schedule B End Use is listed as industrial machines, other. NAICS classification category 333415: air-conditioning and warm air heating equipment and commercial and industrial refrigeration equipment manufacturing.
This information was last updated on Jul 01, 2025.