331511 Iron Foundries

Official definition

This U.S. industry comprises establishments primarily engaged in pouring molten pig iron or iron alloys into molds to manufacture castings (e.g., cast iron manhole covers, cast iron pipe, cast iron skillets). Establishments in this industry purchase iron made in other establishments.

Source: US Census Bureau, 2022 NAICS descriptions.

When to use a different code

Census classifies these close-sounding activities somewhere else. Businesses mainly engaged in:

• Establishments primarily engaged in manufacturing iron castings and further manufacturing them into finished products are classified based on the specific finished product.

Source: US Census Bureau, 2022 NAICS cross-references.

Activities listed under 331511

The Census index assigns these 27 activities to this code. If your business matches one, this is your code.

• Cast iron brake shoes, railroad, manufacturing
• Cast iron pipe and pipe fittings manufacturing
• Cast iron railroad car wheels manufacturing
• Castings, compacted graphite iron, unfinished, manufacturing
• Castings, malleable iron, unfinished, manufacturing
• Castings, unfinished iron (e.g., ductile, gray, malleable, semisteel), manufacturing
• Cooking utensils, cast iron, manufacturing
• Ductile iron castings, unfinished, manufacturing
• Ductile iron foundries
• Fittings, soil and pressure pipe, cast iron, manufacturing
• Foundries, iron (i.e., ductile, gray, malleable, semisteel)
• Gray iron foundries
• Industrial molds, steel ingot, manufacturing
• Iron castings, unfinished, manufacturing
• Iron foundries
• Malleable iron foundries
• Manhole covers, cast iron, manufacturing
• Molds for casting steel ingots manufacturing
• Molds, steel ingot, industrial, manufacturing
• Pearlitic castings, malleable iron, unfinished, manufacturing
• Pipe and pipe fittings, cast iron, manufacturing
• Pipe couplings, cast iron, manufacturing
• Rolling mill rolls, iron, manufacturing
• Semisteel foundries
• Sewer pipe, cast iron, manufacturing
• Soil pipe, cast iron, manufacturing
• Water pipe, cast iron, manufacturing

Source: US Census Bureau, 2022 NAICS index file.

SBA size standard for 331511

To count as a small business for SBA loans and federal contracts under NAICS 331511, your business (including affiliates) must not exceed 1,000 employees. Check your business.

Source: SBA table of size standards, effective March 17, 2023.

Closest UK SIC 2007 codes

There is no official one-to-one link between NAICS and UK SIC. These codes share the same international class (ISIC Rev. 4: 2431, 2823), so treat them as a starting point and check the definition.

• 24310Cold drawing of barsUK SIC
• 28230Manufacture of office machinery and equipment (except computers and peripheral equipment)UK SIC

Built from Census concordances 2022→2017 NAICS and 2017 NAICS→ISIC Rev. 4.

Similar codes to compare

• 331512Steel Investment Foundries
• 331513Steel Foundries (except Investment)