333131

Mining Machinery and Equipment Manufacturing

Manufacturing › Machinery Manufacturing › Agriculture, Construction, and Mining Machinery Manufacturing

SBA Size Standard

900 employees

Employee-Based Verify at SBA.gov →

NAICS Code Hierarchy

33

Sector

Manufacturing

333

Subsector

Machinery Manufacturing

3331

Industry Group

Agriculture, Construction, and Mining Machinery Manufacturing

333131

National Industry (This Code)

Mining Machinery and Equipment Manufacturing

Official NAICS Description

Source: U.S. Census Bureau 2022 NAICS

📘 Source: U.S. Census Bureau — 2022 NAICS Manual
This U.S. industry comprises establishments primarily engaged in (1) manufacturing underground mining machinery and equipment, such as coal breakers, mining cars, core drills, coal cutters, and rock drills, and (2) manufacturing mineral beneficiating machinery and equipment used in surface or underground mines.

✓ Small Business Eligibility at a Glance

Based on SBA Table of Small Business Size Standards (2024)

Size Standard

900 employees

Measurement Period

Current count

Standard Type

Employee-Based

Applies To

All contracts under NAICS 333131

Set-Aside Programs

8(a), WOSB, HUBZone, SDVOSB

Certification Required

No (self-certify in SAM.gov)

Size standards are set by the SBA and reviewed periodically. Always verify at SBA.gov before bidding.

Cross-References

The following activities are classified elsewhere in the NAICS system:

Manufacturing surface mining machinery and equipment--are classified in Industry 333120, Construction Machinery Manufacturing;
Manufacturing well drilling machinery--are classified in U.S. Industry 333132, Oil and Gas Field Machinery and Equipment Manufacturing;
Manufacturing coal and ore conveyors--are classified in U.S. Industry 333922, Conveyor and Conveying Equipment Manufacturing; and
Manufacturing underground mining locomotives--are classified in Industry 336510, Railroad Rolling Stock Manufacturing.

How to Use NAICS 333131 in SAM.gov

NAICS code 333131Mining Machinery and Equipment Manufacturing — is used in SAM.gov to identify businesses whose primary activity falls within this classification. When you add this code to your SAM.gov entity registration, contracting officers searching for vendors in the Agriculture, Construction, and Mining Machinery Manufacturing space will be able to find your business.

If this code represents your primary business activity, designate it as your primary NAICS code. Your primary NAICS code determines your size standard for any contract solicited under this code. With a size standard of 900 employees, your business must be at or below this threshold to qualify as a small business for set-aside contracts under NAICS 333131.

Log in Entity Registration Goods & Services Add NAICS Code Enter 333131 Save

Frequently Asked Questions

What is NAICS code 333131?

NAICS code 333131 is 'Mining Machinery and Equipment Manufacturing', classified under the Manufacturing sector (NAICS 33). This U.S. industry comprises establishments primarily engaged in (1) manufacturing underground mining machinery and equipment, such as coal breakers, mining cars, core drills, coal cutters, and rock d

What is the SBA small business size standard for NAICS code 333131?

The SBA defines a small business under NAICS code 333131 (Mining Machinery and Equipment Manufacturing) as one with 900 employees. This size standard determines eligibility for small business set-aside contracts, 8(a), HUBZone, WOSB, and SDVOSB programs in SAM.gov.

How do I register NAICS code 333131 in SAM.gov?

To register NAICS code 333131 in SAM.gov: (1) Log in at sam.gov, (2) Navigate to your Entity Registration, (3) Go to the Assertions section, (4) Add 333131 (Mining Machinery and Equipment Manufacturing) to your NAICS code list. You may designate one code as your Primary NAICS code.

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Related NAICS Codes

Other codes in Agriculture, Construction, and Mining Machinery Manufacturing

Related PSC Codes

PSC codes commonly used with this NAICS sector

Source: GSA PSC Manual April 2025

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