Understanding National Stock Numbers: A Complete Guide
The military basically runs on spare parts. This sounds far-fetched, but it really isn’t. For the thousands of weapon systems in the inventory, there are millions upon millions of parts of all conceivable shapes and sizes. From the smallest washer and gasket to huge components, every single item is painstakingly tracked. While there are part numbers, these are generally produced by the manufacturer, and there is not a consistent pattern to follow from vendor to vendor.
This is where a standardized numerical system comes in really handy, and that numerical system is the National Stock Number (NSN) system. In fact, the NSN is not just a United States thing: all NATO countries use the NSN system, so there is fast and completely accurate continuity in the supply chain.
We’re going to talk all about the NSN, so you know exactly what it is
What are National Stock Numbers (NSNs)?
Alright, so what exactly are national stock numbers, and why are they so important?
Think of it in these terms: you are tasked with finding a replacement gasket for a hydraulic pump for a C-12 Huron. Where do you even start in the vast supply and logistics system? There are literally millions of parts out there. Heck, there might be millions of gaskets alone; who even knows?
Searching for the right part starts with finding the NSN, which often requires using FEDLOG or similar software to take the part number from the illustrated parts breakdown (IPB) and find the NSN for that weapons system.
Definition and Purpose
National Stock Numbers (NSNs) are a crucial component of federal procurement, created to reduce duplicate items in the federal inventory and standardize military requirements for testing.
In lay terms, the purpose of NSNs is to standardize item identification in the vast supply chain. This ensures a uniform approach to the supply chain process and greatly streamlines the part procurement process.
NSNs are a 13-digit code used to identify and manage every product imaginable, including tires, aircraft parts, hammers, and lightbulbs. And by everything, we really mean everything. If it is in the military services supply chain, it has an NSN.
The main benefits of the NSN system are:
- Standardization: NSN numbers standardize the nomenclature and identification of parts in the supply system. This ensures that all NSN-assigned items are uniquely identified for easy and fast procurement with much lower rates of errors in the process.
- Inventory management: the NSN is a codification system that helps with one-off orders and repeatedly ordered items alike. This is to make tracking items across many locations globally easier and more reliable.
- Procurement: The NSN number radically simplifies the procurement process by providing one single identifier for each item. This significantly improves and streamlines the procurement process.
Each item is assigned a unique number series that provides information about its name, price, physical/performance characteristics, manufacturer, and dimensions. When you plug this pertinent information into FED-LOG®, it brings up exactly what you are looking for, and all information necessary to request and procure the part.
History of NSNs
Let’s take a quick look at the history of the NSN system: how it came to be, and what it is now.
The NSN replaced the Federal Stock Number (FSN) in 1974 and is a unique, item-identifying series of numbers. The FSN was an 11-digit Numeric Code developed by the DoD in 1949 to identify items in the Army-Navy Catalog System. This is important because, as we have talked about several times in the past, logistics was the Achilles heel of the Allied war efforts during World War II. It was painfully apparent that major changes needed to happen in logistics before another significant war because of the amount of loss due to terrible logistical practices and overall loss.
NSN Structure and Components
At first glance, the NSN looks like a clump of random numbers, but that is far from the truth. It is structured to tell a complete story of precisely what the part is, where it comes from, and so on.
Federal Supply Classification Group (FSCG)
The initial subgroup, abcd, is the Federal Supply Classification Group (FSCG) or National Supply Classification Group (NSCG). In theory, similar items would always have closely related numbers in this section of the NSN. The first two digits are the federal stock group, and the second pair of numbers is the federal stock class.
National Item Identification Number (NIIN)
The next nine digits, ef-ghi-jklm, comprise the NIIN (National Item Identification Number). The first two digits of the NIIN (the ef pair) record which country codified the item first.
Why is this part important? Well, because NATO has adopted the NSN so it is important to know who and what is supplied to whom and by whom. For instance, items beginning with 00 and 01 are from the U.S., which means that the receiving country needs to be approved through the FMS program. This is usually a non-issue for NATO nations, but just the same it does apply.
Department of Defense Identification Code (DODIC) and Other Codes
DODIC is an alphanumeric four-symbol code used to identify ammunition and explosives. The code consists of one letter followed by three numerals or two letters followed by two.
Accessing and Using NSN Data
NSN Catalogs and Databases
- The US Catalog covers the order of 6 Million NIINs (Items of Supply) for a total of 13 Million Items of Production (Part Number + Manufacturer reference).
- The NATO Support and Procurement Agency (Capellen, Luxembourg) regularly compiles the catalogs of several member nations for the production of the NATO Master Catalogue of References for Logistics (NMCRL).
Applications in Government Procurement and Inventory Management
So, what exactly do they do in procurement? Well, a part procured doesn’t really do you any good if you end up procuring the wrong part, does it? And this happens all the time, let me tell you.
Say you are looking for windscreen hardware for a windscreen replacement for an aircraft. The hardware tends to all look about the same, but it isn’t always the same. The NSN guarantees that it is correct.
It also simplifies inventory management by providing an utterly reliable and universal means of inventorying parts. See, here’s the funny thing about part numbers: they are not universal. Every manufacturer has their own standard, so you can end up with duplicates that are not even close to the same thing. But there is only one NSN.
NSN Lookup and Matching
The stock number lookup is really important because the stock number is how parts actually get ordered. There might be dozens of different parts that all use the same part number, or the part numbers might be in different formats, which are not supported in DoD supply systems.
So, you have to find a way to look up the NSN via the parts number.
What is an NSN Lookup?
NSN lookup, or National Stock Number Lookup, is a process used to identify an item based on its assigned NSN number. This type of search is almost exclusively used by government agencies, military personnel, and aerospace companies to find a part’s National Stock Number.
In military aviation, there are a couple of ways to acquire the part number of any given part or component: first, the part number from the manufacturer may be stamped or printed on the part. Second, the federal supply system part numbers are listed in the Illustrated Parts Breakdown (IPB) for every single MDS in the inventory. From this, you can determine the NSN data and NSN assignment. The IPB also has a considerable amount of associated data that is useful for proper parts identification.
Matching Part Numbers to NSNs
Use National Stock Numbers (NSNs) to identify parts with higher frequency, as used by the U.S. Department of Defense. For example, the Dapco 2100 NSN number is 8030-01-471-0604, which can be found using the search box or filtered by NSN or manufacturer.
The most common and reliable way to the NSN assignment of a DoD component is through FED LOG ®. FED LOG ® is a web-based software system that catalogs millions of NSNs which are searched through a few different characteristics.
Historically, FED LOG® was available on CD-ROM or DVD, allowing users to access information on management, part/reference numbers, suppliers, Commercial and Government Entity (CAGE) codes, freight, Interchangeability and Substitutability (I&S), and other characteristics linked to National Stock Numbers (NSNs). It also included unique service data for enhanced search capabilities. Most users have shifted to downloading files from FedMall (link provided above) or the Air Force Portal in recent years.
FED LOG® enables users to access Federal Logistics Information System (FLIS) data when internet access is unavailable. It provides critical supply information such as NSNs, approved and non-approved item names, manufacturer and distributor details (including part numbers), freight information, hazardous material indicators, interchangeability and substitutability data, Acquisition Advice Codes (AAC), unit prices, and physical and performance characteristics, along with service-specific management data.
In short, you punch in the correct part number, and it spits out the national stock number. Then, you can proceed to order the part.
Greenwood’s Part In the Process
Greenwood Aerospace is here to support the end users. We are your parts procurement specialists who populate your supply chain. Military aviation rides on the back of reliable logistics, and we are the most reliable logisticians in your wheelhouse. For over forty years, we have been forming relationships with the best parts suppliers in the business.
Not only can Greenwood Aerospace source your parts, but we can warehouse them in our 42,000-square-foot facility in Ponca City, Oklahoma.
Do you have a parts purchase order to source? Whether it’s a big batch of items or sourcing the one really hard-to-find part for your hangar queen that’s got to get back in the air, we have the connections in the parts industry to find it. Start your quote today, and we’ll get you back in the air!
.svg)
