NAICS code for a machine shop or metal fabrication shop

This page is for machine shop and fab shop owners registering in SAM.gov, applying to a supplier portal or filling in a loan form, and for sellers of tooling, software, materials and services building a list of shops.

The NAICS codes for machine shops and metal fabrication

All of these sit in Subsector 332, Fabricated Metal Product Manufacturing.

How to choose

Start with two questions: do you work to the customer's drawing, and do you mainly remove material or join it? A shop that machines parts to order is 332710. A shop that cuts, bends and welds metal into assemblies is a fabricator, and the product decides the code.

The last row is our reading of "on a job or order basis": if you design and sell your own product, you're a manufacturer of that product, not a machine shop. Where a shop does several of these, use the one that brings in the most revenue as the primary code and list the rest as secondary codes. SAM.gov lets you list several, and federal buyers search by them.

SIC codes for machine shops

The SIC code for a machine shop is 3599, Industrial and Commercial Machinery and Equipment, NEC. SIC 3599 is a catch-all, so the Census concordance maps it to seven NAICS codes: 332710 Machine shops, 332813 Electroplating and anodizing, 332999 Other fabricated metal products, 333310 Commercial and service industry machinery, 333998 Other general purpose machinery, 334519 Measuring and controlling devices, and 336390 Other motor vehicle parts. The fabrication codes have SIC equivalents of their own:

A SIC 3599 list therefore mixes machine shops with makers of car parts and measuring devices. The SEC's own SIC list has no 3599: machinery companies file under 3590, and custom manufacturers often under 3440, Fabricated Structural Metal Products. To convert other codes, use the NAICS to SIC converter.

How many machine shops and fab shops there are

County Business Patterns (CBP) 2023, establishments with paid employees:

Machine shops are small: 13 employees per location on average, against 33 at structural steel fabricators and 28 at sheet metal shops (our calculation). Payroll works out to about $63,700 per machine shop employee.

California has the most machine shops (2,221), followed by Texas (1,312), Ohio (1,112), Michigan (943) and Pennsylvania (901). CBP counts locations with paid employees, not companies, and it uses NAICS 2017; these codes didn't change in 2022.

SBA size standards

Manufacturing standards count employees, not revenue: the average number of people employed in each pay period over your latest 24 calendar months, including affiliates. From the SBA's Table of Size Standards, effective March 17, 2023 (13 CFR 121.201 on the eCFR shows no later change):

The jump between columns matters. A 120-person shop with $30 million in sales is small for a 332710 contract but not for an 811310 repair contract, so check the code on every solicitation.

Where the code is used and what a wrong one costs

• Federal contracts and subcontracts. The contracting officer assigns one code per contract, and your size is measured against it. If you think the code on a solicitation is wrong, any interested party can appeal it to the SBA's Office of Hearings and Appeals within 10 days of its publication.
• Tax returns. The IRS list doesn't split the subsector: machine shops and every fab shop use 332000, Fabricated metal product mfg., on Schedule C, while machinery and welding repair use 811310.
• Insurance and lenders. A machining job shop, a structural fabricator and a welding repair business carry different risks. Use the code for what earns most of your revenue.

Finding machine shops and fabricators by code

Public companies are few. On EDGAR, look under SIC 3440 and SIC 3590:

The other 17,000 machine shops are private and mostly small. SAM.gov registrations, state manufacturing directories and supplier lists from OEMs are the usual public sources. A Bebop search can describe the shops you want (5-axis CNC job shops with 20 to 100 employees, AS9100 certified, in Ohio) and return the companies and owners with the reason each fits.

Worked example: coding a mixed shop

Illustrative example. The shop and figures are invented.

Ridgeline Precision (ridgeline.example) in Michigan has 85 employees and $14 million in sales: $9 million of CNC-machined parts to customer drawings, $3.5 million of welded frames and weldments, and $1.5 million of machine rebuild and repair work.

1. Primary code. Machined parts are 64% of sales ($9 million of $14 million), so the primary code is 332710.
2. Secondary codes. Weldments go under 332313 and the repair work under 811310.
3. Size check. With 85 employees it's small under 332710 (500) and 332313 (750). For an 811310 repair contract the test is receipts: a five-year average of, say, $13 million is over the $12.5 million limit.
4. SIC. A form asking for SIC gets 3599; the IRS code on its return is 332000.

Next step: if you sell to manufacturers, read the guide to manufacturing companies for who buys and how to reach them.