Stamped Out

Federal Stock Number (FSN)

The Federal Stock Number of an item of supply consists of the applicable 4-digit class code number from the Federal Supply Classification plus a sequentially assigned 7-digit National Item Identification Number. The number shall be arranged as follows:
4210-196-5439.

Effective 30 September 1974, all FSN's were converted to NSN's.


To convert a FSN into a NSN you need to do the following:
1. Take your FSN (Example- 6625-553-0142) and the NCBC (Example- 00)
2. Split the FSN at the FSC and insert the NCBC (Example- 6625-00-553-0142) and now you have a NSN