Explainer
What Is an NSN?
The Short Answer
One Number for One Item of Supply
DLA describes the National Stock Number (also called a NATO Stock Number) as the official label for an item of supply that is repeatedly procured, stocked, stored, issued, and used across the federal supply system. It exists so every service and allied nation calls the same washer, lamp, or fuse by the same identifier, which is why DLA calls it the international language of logistics.
The data behind each NSN sits in the Federal Logistics Information System (FLIS), run by DLA Logistics Information Services. DLA reports more than 7 million active NSNs in it. For anyone writing parts data or technical manuals, the NSN is the key that ties a printed part line to a supply record.
Structure
Thirteen Digits, Three Parts
- FSC: the first four digits
- The Federal Supply Class groups like items. DLA's example is 6240, the class for electric lamps, which covers fluorescent, incandescent, mercury, and sodium lamps alike.
- NCB code: the next two digits
- The National Codification Bureau code says which country's bureau assigned the number. Codes 00 and 01 both identify the United States. It does not say where the part was made.
- Item number: the last seven digits
- Non-significant and assigned sequentially. Nothing in these digits tells you what the item is. The two NCB digits plus these seven are the NIIN (National Item Identification Number), and the FSC plus the NIIN make the NSN.
Written out, 6240-00-357-7976 is class 6240, a United States number, item 357-7976. Because the last seven digits carry no meaning, you cannot work out the item from the number; you look it up in FLIS. Do not infer that two NSNs in the same class are related, or that a gap between item numbers means anything.
Getting One
How an Item Gets an NSN
An NSN is the result of cataloging. DLA defines it as the process in which an item of supply is named, assigned a Federal Supply Class, described by its characteristics and performance data, and then assigned an NSN. DLA Logistics Information Services in Battle Creek, Michigan assigns every NSN, at the request of a military service, certain federal and civil agencies, or an international partner.
Manufacturers and suppliers cannot request an NSN. A request starts when a government need for the item is identified, then travels through the supply chain to cataloging. For allied customers the assignment is a government-to-government step through a National Codification Bureau. Two triggers matter to publication teams. One is a non-stocked item that keeps being ordered. The other is a new weapon system, where the service runs provisioning, an up-front review that identifies all potential spares and submits the NSN requests.
That is where your data comes in. The record DLA assembles includes the item name, the manufacturer's part number, physical and performance characteristics, shipping and storage data, and more. The manufacturer's part number is the reference the cataloger works from, and the company behind it is identified by its CAGE code, the identifier any business with a government needs. If the part number, the CAGE code, or the item description in the provisioning data is wrong, the catalog record starts out wrong.
In Technical Manuals
Where NSNs Show Up
In a defense technical manual, the NSN lives in the parts data. A repair parts list or an illustrated parts catalog pairs each figure item with its part number and, for items that have one, a stock number that lets a maintainer requisition the part. Army lists add supply data such as SMR codes beside it. In S1000D the same information is carried as illustrated parts data.
The NSN usually does not originate in the manual. It comes from the program's support analysis and provisioning data. Logistics support analysis produces the item records, the S3000L data model structures them for the international side, and the integrated product support elements place supply support and technical data in the same plan. The parts list in a manual is a downstream view of that data, so an NSN error in a manual is usually an error upstream that was copied forward. For the procurement-side exchange, see S2000M.
Data Problems
Where NSN Data Goes Wrong
- Part number treated as the NSN, or the reverse
- A part number belongs to a manufacturer's design. An NSN belongs to an item of supply, and one NSN can record more than one manufacturer. A parts list that carries only one of the two cannot be matched cleanly to the other.
- A part number with no CAGE code
- Part numbers repeat across companies. Without the CAGE code of the manufacturer or design activity, the same string can point at two different items, and a lookup returns the wrong one or none.
- Superseded and changed items
- DLA says the NSN record is updated over the item's life for new manufacturers, price changes, and part number changes. A manual frozen at publication can cite a part number or NSN that has since changed. Check the current record, not the printed page.
- Typing and formatting errors
- NSNs are usually written with hyphens (4-2-3-4). Dropped digits, a transposed pair, or a spreadsheet that strips leading zeros all produce a number that looks plausible and matches nothing.
- NSN assumed for every part
- Not every part in a manual has an NSN. NSNs go to items of supply that are repeatedly procured and stocked. A line without one may be correct as delivered.
The fix is the same in each case: keep the part number, the CAGE code, and the NSN as separate fields in your source data, validate the NSN as 13 digits, and check the stock number against the current FLIS record before delivery rather than copying it from an older manual.
Our Part
Provisioning and Cataloging Data
Shakewell supports provisioning and cataloging data, including NSN-ready parts data, alongside technical manuals. Read your contract's data requirements for which items need cataloging data and in what form.
FAQ
Questions We Hear
What does NSN stand for?
National Stock Number. The same number is called a NATO Stock Number (also NSN) in the NATO Codification System. DLA treats the two terms as the same thing.
How many digits are in an NSN?
Thirteen: a 4-digit Federal Supply Class, a 2-digit National Codification Bureau code, and a 7-digit item number. It is usually written 0000-00-000-0000. DLA's example is 6240-00-357-7976.
What is the difference between an NSN and a NIIN?
The NIIN is the last nine digits of the NSN, with the FSC dropped. Since the FSC is the part that groups items by class, the NIIN is what identifies the individual item. The NSN is the FSC plus the NIIN.
Can a manufacturer or supplier request an NSN?
Not directly. DLA states that manufacturers and suppliers do not have the authority to request an NSN. A military service, NATO country, federal or civil agency, or a contractor-supported weapon system requests it once a need for the item is identified, and DLA Logistics Information Services assigns it. A manufacturer can supply the technical data cataloging needs.
Is a CAGE code the same as an NSN?
No. A CAGE code identifies a company or entity doing business with a government. An NSN identifies an item of supply. The two meet in a catalog record, where a manufacturer's part number is tied to the CAGE code of the company that uses it.
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Get Your Parts Data NSN-Ready
Send us a sample parts list and the provisioning data behind it. We will tell you what is missing between your part numbers and a clean catalog request.