Registry · SIC Index · Group 33

SIC 3321 — Gray and Ductile Iron Foundries

SIC 3321 is 'Gray and Ductile Iron Foundries', a 4-digit Standard Industrial Classification (SIC) code under Major Group 33: Primary Metal Industries (Division D: Manufacturing); it maps to modern 2022 NAICS code(s): 331511 (Iron Foundries).

Description & Classification

SIC code 3321 representing 'Gray and Ductile Iron Foundries' is an industry category in the Standard Industrial Classification (SIC) system under U.S. OSHA and Federal procurement registers.

Modern NAICS Crosswalk

Trace the modern equivalent classifications in the 2022 North American Industry Classification System (NAICS) database:

Classification Details

SIC Code3321
Industry TitleGray and Ductile Iron Foundries
DivisionDivision D: Manufacturing
Major GroupMajor Group 33: Primary Metal Industries
Source / VerifiedUS Census 1987 SIC Concordance / 2026-06-28

Related Resources & Compliance Guides

Further regulatory reference links for legacy SIC code 3321:

Related Industries in Major Group 33

3312 - Steel Works, Blast Furnaces...3313 - Electrometallurgical Products, Except St...3315 - Steel Wiredrawing and Steel Nails and Sp...3316 - Cold-Rolled Steel Sheet, Strip, and Bars...3317 - Steel Pipe and Tubes...3322 - Malleable Iron Foundries...3324 - Steel Investment Foundries...3325 - Steel Foundries, NEC...

Frequently Asked Questions (FAQ)

What industry does SIC code 3321 represent?

SIC 3321 is 'Gray and Ductile Iron Foundries', a 4-digit Standard Industrial Classification (SIC) code under Major Group 33: Primary Metal Industries (Division D: Manufacturing); it maps to modern 2022 NAICS code(s): 331511 (Iron Foundries).

What is the modern 2022 NAICS mapping for SIC 3321?

SIC code 3321 maps to modern NAICS codes: 331511 - Iron Foundries.