Blog What is FSG & FSC? What is the process o..

What is FSG & FSC? What is the process of the Federal Supply Classification System?

To explain the federal supply classification system, we must first understand what a National Stock Number is. National Stock Numbers or NSNs, are 13-digit serial numbers assigned to all standardized items within the federal supply chain. All components that are used by the U.S Department of Defense are required to have an NSN, the purpose of which is to provide a standardized language of naming components. Also known as NATO stock numbers, NSNs are recognized by all NATO countries. NSNs are assigned by the Defense Logistics Agency  and are typically in the format XXXX-XX-XXXXXXX.

NSN are  broken down into smaller subcategories, each providing individual information about the component. To begin, 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.

In the aerospace industry a key federal supply group is FSG 15: Aircraft and Airframe Structural Components. The Department of Defense produces a cataloging handbook known as the H2, which lists all the current federal supply groups and their subclasses. It is a handy reference guide for the classification of any NSN. Fixed wing components for use on aircraft are found under Federal Supply Group 15 and Federal Supply Class 10. If you are looking at a seemingly incomprehensible list of NSNs, you can simply look at the first four digits and you will at least know what commodity area the item belongs to.

The remaining 9 digits of the NSN are made up of the 2-digit country identifier followed by the 7 National Item Identification Number (NIIN). The US for example,  has the country identifier, 00. Unlike the FSCG, the NIIN is unique to the item itself.

The federal supply classification system is designed to help make the parts supply chain more accessible and uniform. Without FSGs, FSCs, or NSNs, it would be difficult for manufacturers and suppliers to determine what exactly they were buying and selling. A common place hardware components, manufactured in the millions, may be called one thing by one manufacturer, while having an entirely different name somewhere else. This is why the DoD moved to implement a complete naming and classification system. 

At ASAP Distribution, owned and operated by ASAP Semiconductor, we have a wide-ranging list of NSN parts, FSCs, and FSGs  for you to source parts from. Our helpful search engine lets you type in the exact NSN you need. As a premier supplier of parts for the aerospace and defense industries, we’re always available and ready to help you find all the parts you need. For a quick and competitive quote, email us at or call us at +1-714-705-4780.


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