Posted on October 1, 2019 John Symond
The aerospace and defense industries are hectic industries that require a lot of information to be shared in a small amount of time. Part sourcing needs to be quick and efficient in order to accommodate for costly situations such as Aircraft on Ground (AOG). The NSN systems was developed by the U.S. Department of Defense and is a key reason why the federal supply chain runs so efficiently today.
The premise behind the National Stock Number (NSN) system is uniformity and a set standard of communication. During WWII, the military found it difficult to quickly and efficiently source parts from manufacturers as there was no formal naming system. A part could have multiple names depending on the manufacturer that made it. This lack of a formal naming system led to inconsistencies in stock levels as there would be a surplus of components in one area and a deficit in another. In response to these issues, the DoD set out to form a uniform system that could be understood across countries with language barriers.
The key part of the NSN system is the 13-digit identification number that is assigned to all components that are sourced, stocked, and procured within the federal supply chain. NSNs are made up various subcategories that each provide more information about the individual component. The first four digits of the NSN are known as the federal supply group classification code (FSCG), which is further broken down to the federal supply group (FSG) and the federal supply class (FSC). The FSG is the first two numbers of the NSN and details which of the broad groups the component belongs to. In the aerospace industry federal supply group 15: aircraft and airframe structural components is important. The following 2-digits are the federal supply classification, which is the exact sub-category that the component belongs to. FSCG 1510 is under FSG 15 and includes fixed wing aircraft components.
The remaining nine digits of the NSN include the 2-digit country code and the 7-digit National Item Identification Number (NIIN). The NIIN is a random number assigned to the component, unlike the FSC or FSG the NIIN doesn’t further classify an item. A NIIN more or less tells you what the item is. The DLA uses a sequential system to generate the NIINs. It is possible to source parts using their NIIN, however it is more common to source parts using the full NSN.
NSNs and NIINs are not necessarily something to compare, but rather understand how they work together to identify an individual component. Without NSNs or NIINs it would be very difficult to tell one fastener from the next for example. Even larger aircraft components such as landing gear assemblies benefit from a clear naming system. Buy NSN stocks many different NSNs and NIINs that are all helpfully categorized on our website.