NSN to Part Number: How to Find and Buy the Part Behind a Stock Number
A requisition, a contract line or a DLA solicitation hands you a 13-digit number. Nobody manufactures an NSN. Somewhere behind it is a part number you can actually buy, and getting from one to the other is where most of the mistakes happen.
Every NSN in the Federal Logistics Information System (FLIS) carries one or more reference numbers: a manufacturer or design-activity part number paired with a CAGE code. Those are what you quote, buy and inspect against. Which of them is acceptable is decided by your drawing or contract, not by the NSN record alone.
What the 13 digits mean
Take 5935-01-167-6118:
| Digits | Example | What it is |
|---|---|---|
| 1–4 | 5935 | Federal Supply Class (FSC). The first two digits are the group (59 = electrical and electronic equipment components); all four narrow it to a class (5935 = electrical connectors). |
| 5–6 | 01 | NATO country code of the bureau that assigned the number. 00 and 01 are the United States. |
| 7–13 | 167-6118 | Serial assigned by that bureau. It carries no meaning on its own. |
| 5–13 | 011676118 | NIIN (National Item Identification Number). The item's real identity; the FSC can change if an item is reclassified, the NIIN does not. Most systems, ours included, index on it. |
The FSCs you will see most in electronics: 5905 resistors, 5910 capacitors, 5935 connectors, 5945 relays, 5950 coils and transformers, 5961 semiconductor devices, 5962 microcircuits and 5999 miscellaneous electrical. Hardware that travels with electronics shows up in the 53xx group: 5305 screws, 5306 bolts, 5310 nuts and washers, 5315 pins and keys, 5320 rivets.
One NSN, several part numbers
An NSN describes a need: an item of supply that does a defined job. Over the years, several manufacturers' part numbers can get recorded against the same NIIN, alongside the military specification number and sometimes a prime contractor's drawing number. Each reference number is paired with the CAGE code of the company or government activity that controls it.
FLIS also codes each reference number for what kind of reference it is. Two fields do the work: the Reference Number Category Code (RNCC), which says whether the number is, for example, a design-control or specification reference or simply a vendor's item, and the Reference Number Variation Code (RNVC), which says whether it fully identifies the item or is only informative. Read those before treating any listed number as a drop-in.
How to buy against an NSN, step by step
- Confirm the NSN is live. Cancelled NSNs often point to a replacement. Quoting a dead number wastes a cycle and can get a bid rejected.
- Pull the reference numbers and CAGE codes. DLA's public WebFLIS search, or the NSN lookup on our site, shows them along with the item name and characteristics.
- Read your contract. Does it call out one part number, a specification (for example a D38999 or JANTXV part), a list of approved sources, or just the NSN? That answer decides which reference numbers you may accept.
- Check for supersession. Older MS numbers are often superseded by newer M- or D-prefixed specification numbers, and CAGE codes change when companies are acquired. The same item can look like three different part numbers across old paperwork.
- Send the whole picture in your RFQ. NSN, the reference part number and CAGE you need, quantity, date-code limits, and the paperwork you require: certificate of conformance, traceability, test reports, and military packaging and marking if the parts ship to a government depot.
- Inspect against the part number, not the NSN. Markings, finish and dimensions are verified against the manufacturer's part, so the part number is what your receiving inspection needs.
Where NSN purchases go wrong
- Searching the wrong form. Systems differ on dashes and on whether they want 13 digits or the 9-digit NIIN. If a search comes back empty, try the NIIN alone.
- Assuming interchangeability. The cheapest reference number under an NSN may differ in finish, temperature range or screening level from the one your program qualified.
- Ignoring the CAGE. The same part number string can belong to two different companies. The CAGE code is what makes a reference number unique.
- Losing the documentation trail. Defense buyers increasingly need traceability back to the manufacturer. Ask for it before you place the order, not after the parts arrive.
How RH Electronics handles NSN requirements
Our catalog is indexed by NSN and NIIN, so a stock number in our search resolves straight to the reference part numbers and CAGE codes recorded against it. We show those as recorded and label them as NSN matches; we don't claim equivalence your drawing hasn't granted. Send us the NSN, the part number you need and your quality requirements, and we'll answer with what's in stock, what can be sourced, the date codes, and the documentation that ships with it. RH Electronics holds CAGE code 3CDL5, is ISO 9001:2015 certified, and participates in ERAI and GIDEP.
Common questions
What is the difference between an NSN and a NIIN?
The NSN is the full 13 digits: a 4-digit Federal Supply Class followed by the 9-digit NIIN. The NIIN identifies the item; the FSC only classifies it and can change if the item is reclassified. Many databases index on the NIIN.
How do I find the manufacturer part number for an NSN?
Look up the NSN in DLA's WebFLIS or in an NSN-indexed catalog such as ours. The record lists reference numbers, each a part number paired with a CAGE code. Your contract or drawing decides which of them you may buy.
Are all part numbers listed under one NSN interchangeable?
Not automatically. They have been catalogued against the same item of supply, but your drawing, specification or qualified sources list decides what is acceptable for your program. Check the reference-number codes and your contract before substituting.
What does a CAGE code tell me?
A CAGE (Commercial and Government Entity) code identifies the company or government activity that controls a part number. Two companies can use the same part number string; the CAGE code tells you whose part it is.