NAICS 321918 to SIC Code Crosswalk
The NAICS code 321918 (Other Millwork (including Flooring)) maps transitively to legacy 1987 SIC classification code(s): 2421, 2426, 2431.
Concordance Concordance Mapping Asset
| Source Code | Source Industry | Target Code | Target Industry | Relation | Concordance Path |
|---|---|---|---|---|---|
| NAICS 321918 | Other Millwork (including Flooring) | SIC 2421 | Sawmills and Planing Mills, General | Many-to-Many | SIC1987:2421 → NAICS1997:321918 → 2002:321918 → 2007:321918 → 2012:321918 → 2017:321918 → 2022:321918 |
| NAICS 321918 | Other Millwork (including Flooring) | SIC 2426 | Hardwood Dimension and Flooring Mills | Many-to-Many | SIC1987:2426 → NAICS1997:321918 → 2002:321918 → 2007:321918 → 2012:321918 → 2017:321918 → 2022:321918 |
| NAICS 321918 | Other Millwork (including Flooring) | SIC 2431 | Millwork | Many-to-Many | SIC1987:2431 → NAICS1997:321918 → 2002:321918 → 2007:321918 → 2012:321918 → 2017:321918 → 2022:321918 |
Why Concordances Don't Line Up 1:1
The Standard Industrial Classification (SIC) system was established in 1937 and last updated in 1987, organizing businesses by end products. The North American Industry Classification System (NAICS) replaced it in 1997, classifying establishments by production processes. Because of this structural shift, many-to-many relationships are common, requiring chained concordance steps to bridge the historical gap.
Reverse Crosswalk: Going the other way? See the mapping at SIC 2421 to NAICS, SIC 2426 to NAICS, SIC 2431 to NAICS.
Related Pages & Tools
- NAICS Code 321918 Profile — Official definition, SBA size standards, and establishment statistics.
- Sector 31-33 Hub (Manufacturing) — Category directories.
- Interactive Crosswalk Engine — Convert any SIC or NAICS code dynamically.
Primary Ingestion Source
Data sourced from the U.S. Census Bureau Concordances (1997, 2002, 2007, 2012, 2017, and 2022 editions). Last verified on 2026-06-30.