What is NSN and Who Assign NSN?

National Stock Numbers (NSNs) are assigned by the U.S. Defense Logistics Agency, which is a sub-branch of the U.S. Department of Defense. All items that are stocked, sourced, and procured within the U.S federal supply system is assigned an NSN by the DLA. A manufacturer can not request an NSN. Instead, there must be an official need for the component from either the U.S. military itself, a government contractor, or a NATO country. Also known as NATO number, NSNs are officially recognized by all the NATO countries. Although a U.S. based program, components manufactured outside the U.S. are eligible for NSNs.

The idea of the NSN system stems back to WWII where the need for components was understandably high. It became apparent however, that there was no clear identification system for parts, which meant that there was often a surplus of parts in one place, but a deficit in others. Manufacturers also had free liberty to name their parts, so one part had multiple different names. From an efficiency point of view, part sourcing during WWII was ineffective and necessitated change.

NSNs are easily identifiable as a 13-digit serial numbers that are usually in the format xxxx-xx-xxxxxxx. The first four digits of the NSN are known as the Federal Supply Classification Group. The FSCG determines which of the 645 subclasses an item belongs to. The FSCG is further split into the Federal Supply Group (FSG) and the Federal Supply Classification (FSC). The FSG is made up of the first two digits of the NSN which determines which of the 78 groups an item belongs to. The second 2 digits make up the FSC, which determines the subclass an item belongs to. The remaining 9 digits are made up of the 2-digit country identifier followed by the 7 digit National Item Identification Number (NIIN). The US for example, has the country identifier, 00. The Department of Defense publishes the H2 handbook that lists all the current federal supply groups and classes. This is a handy reference guide for aviation and defense components as it lists all the part inclusions and exclusions in the federal groups and classes.

There are 10s of millions of NSNs within the federal supply system. Due to the sheer number of NSNs, the DoD relies on other suppliers to regulate the supply chain. Using NSNs, parts can be located and sourced from all NATO countries in an efficient manner. Independent suppliers such as ASAP Parts Online can source and distribute all different categories of NSNs for the aerospace and defense industries. Owned and operated by ASAP Semiconductor, ASAP Parts Online has an inventory of over 2 billion NSNs. We make sure to list all our NSNs alongside their corresponding sourcing information such as FSC, FSG, NIIN, and the manufacturer. Visit our website, ASAP Parts Online, or call us at +1-702-919-1616 to learn more about NSNs or begin sourcing today.

1. mary wilson
2. Posted on October 1, 2019
3. aviation

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