WOW! Flashback!!!!
When I saw the title of this thread I immediately thought about an issue of PS magazine that I read 30 years ago.
So then I open the thread and Cranetruck (Bjorn) has posted a picture that has been in my noggin all these years.
I was forced to use the federal supply system for 25 years, some may say that I fought against it. Many times I lost, a few times I won. One incredible loss was in the DMZ between Saudi Arabia and Iraq. We had used up our yearly issue of 100,000 rounds of 7.62 ammo in one month. So now our M60's were about to fall silent. The supply wienies refused to give us more ammo until our next fiscal year began. (1 October) I even shouted on the SATCOM at a full-bull supply type at the pentagon. All I got was a refusal and an ass-chewing. "We have met the enemy and he is us." Someone here will point out the cartoon character who said that. So what does a good Senior NCO do? Takes a convoy down south and steals 200,000 rounds from another unit? Who me? I'll deny that until my deathbed.
Boy, I sure go off on a tangent easily. I'm supposed to be talking about FSN's. Or NSN's, whichever you choose.
The first four numbers are easy, i.e. 2320-
The first four are the FSC (Federal Stock Class) 2320 means something like "Vehicle, Wheeled, Motorized"
You can look up all of the FSC codes on-line, or you can ask me, I have them all. (Not memorized, are you kidding?)
The next two number are interesting, as the PS page points out, prior to 30 Sep 1974, the 5th and 6th NSN numbers did not even exist. So listen, young Grasshopper, you are about to learn something. If those two digits are absent from the part you are holding in your hot little hands, that part was actually MANUFACTURED prior to 30 Sep 1974. If those two digits are 00, then your part was manufactured after 30 Sep 1974, BUT, it was an item that the military had in the federal supply system prior to 30 Sep 1974.
You will find many items manufactured today that still have a 00 in those two positions. Good examples are nuts, bolts and even some parts like air filters and tons of M35A2 stuff.
If those two digits are 01, then your item entered the federal supply system after 30 Sep 1974. Logically then, it was also manufactured after Sep 1974. You may argue this point, especially if you think that your 01 marked item was in the federal system before Oct 1974, but you would be wrong. It could be extremely similar to a 00 marked item, however something has changed, a minor specification, even something as simple as the rockwell hardening of a bolt qualifies for a new FSN.
Several months ago I ordered a lovely set of data plates for my 1973 Gama Goat. One of them is not going on the Goat. It is the one that shows the FSN of the Goat as 2320-00- whatever. Why not? I'm not a bolt Nazi, but it bothers me because my 1973 Goat would not have a 00 or a 01 in the FSN. Simply because the Goat was made before Sep 1974.
Whew! Almost finished!
What if the part in your hands has a number other than 00 or 01? It's foreign.
I collect some German vehicles used by the US military. The FSN 5th and 6th digits are 12.
That goes for the entire vehicle, 2320-12-164-1613, and for all of it's component parts. The Germans use exactly the same numbering (NSN) system that we do.
Anybody wonder why 30 Sep 1974 was the changeover date?
Well, 1 October 1974 was the first day of the new fiscal year, a big deal in the military. The day when major changes can be introduced.
That's it, I'm done , I'll shut up now.
-Sarge
P.S. Almost forgot, what are the last seven numbers? Easy. That is the part number.