NAICS codes for manufacturing, explained
Manufacturing is NAICS sector 31-33, split into 21 three-digit subsectors and hundreds of six-digit industries. The code is how federal data sorts factories by what they make.
How the codes nest
Two digits give the sector (31-33 for manufacturing), three the subsector (for example 336, transportation equipment), four the industry group (3363, motor vehicle parts) and six the national industry (336390, other motor vehicle parts).
Where they're used
The Census Bureau's County Business Patterns counts establishments and jobs by code, and EPA programs record each facility's codes. We use Census for job totals and EPA for facility lists.
Code versions
NAICS is revised every five years. Some facilities still report older codes, such as 335911 for storage batteries, which became 335910 in 2022. Our product directories count both.