How can I find an industry's SIC or NAICS code?
The Occupational Safety and Health Administration (OSHA) maintains an SIC codes page where you can look up codes by keyword and vice versa.
The US Census Bureau maintains this NAICS code page where you can look up industries by code or keyword.
The NAICS Association maintains a NAICS and SIC lookup page where you can look up an industry by either code, or by industry name. This is useful for identifying equivalent industry codes under both classification systems.