The lexicon of the top500 ( The Encyclopedia for Classification Codes ) explains the codes and definitions in the world of economical classifications.
NAICS Code 3364 Aerospace Product and Parts Manufacturing
The NAICS Code 3364 is described as
Aerospace Product and Parts Manufacturing It belongs to the code group
NAICS Code 336 Transportation Equipment Manufacturing
To this Code "3364" belongs the sub codes
NAICS Code 33641: Aerospace Product and Parts Manufacturing