NAICS 333612

Overview

The North American Industry Classification System (NAICS) is the U.S. federal standard for classifying business establishments to produce comparable economic statistics across industries. Developed under the Office of Management and Budget with partners in Canada and Mexico, NAICS replaced the Standard Industrial Classification (SIC) in 1997. The current U.S. edition is NAICS 2022, which provides standardized definitions, cross-references, and tools used across government and industry for analysis and reporting. ³

Within NAICS 2022, 333612 covers establishments primarily engaged in manufacturing gears, speed changers, and industrial high‑speed drives (excluding hydrostatic transmissions). Cross‑references direct motor‑vehicle power transmission equipment to 336350, aircraft power transmission equipment to 336413, and industrial hydrostatic transmissions to 333996. These boundaries distinguish non‑vehicular, non‑aircraft industrial gear and drive products from automotive, aerospace, and fluid power domains. ¹

See also on G2X:

• G2X — NAICS 333612 overview
• G2X — NAICS 333613 Mechanical Power Transmission Equipment Manufacturing
• G2X — NAICS 336350 Motor Vehicle Transmission and Power Train Parts Manufacturing

What this NAICS covers

• Manufacturing spur, helical, bevel, worm, and other industrial gears and matched gear sets. ¹
• Producing non‑vehicle speed changers and speed reducers/increasers for industrial applications. ¹
• Manufacturing industrial high‑speed drive units and assemblies (except hydrostatic). ¹
• Building gearboxes and right‑angle or inline drive units for general industrial power transmission. ¹
• Machining and assembling gear components integral to speed changer and high‑speed drive systems. ¹
• Providing finishing operations (e.g., hobbing, grinding, heat‑treating) necessary to produce gears and high‑speed drive equipment. ¹

Related NAICS and PSC codes

Scope notes and cross‑references

• Includes: manufacturing gears, speed changers, and industrial high‑speed drives; excludes hydrostatic transmissions. ¹
• Excludes: motor‑vehicle power transmission equipment (see 336350). ¹
• Excludes: aircraft power transmission equipment (see 336413). ¹
• Excludes: industrial hydrostatic transmissions (see 333996). ¹

Frequently asked questions

• What products fall under NAICS 333612?

  • Establishments in this industry manufacture gears, speed changers (reducers/increasers), and industrial high‑speed drives, with hydrostatic transmissions explicitly excluded. The scope focuses on non‑vehicular, general industrial power transmission equipment rather than automotive or aerospace applications. ¹

• How is 333612 different from 333613?

  • 333612 covers gears, speed changers, and industrial high‑speed drives. 333613 covers other mechanical power transmission equipment such as clutches, brakes (non‑electromagnetic), couplings, universal joints, and plain bearings. Speed changers and gears are directed to 333612. ¹

• Are motor‑vehicle transmissions and related parts included in 333612?

  • No. Motor‑vehicle transmission and power train parts are classified under NAICS 336350, not 333612. This ensures automotive power transmission manufacturing is distinguished from general industrial gear and speed changer production. ¹

• Are aircraft gearboxes or power transmission components part of 333612?

  • No. Aircraft power transmission equipment, including gearboxes and related components designed for aerospace use, is classified under NAICS 336413, not within 333612. ¹

• Where are hydrostatic transmissions classified?

  • Industrial hydrostatic transmissions are not included in 333612; they are classified under NAICS 333996, which covers fluid power pumps and motors and related hydrostatic systems. ¹

Useful resources

• G2X — NAICS 333612 overview
• U.S. Census Bureau — 2022 NAICS Manual (official definitions and cross‑references). ¹
• U.S. Census Bureau — NAICS main page (history, structure, and tools). ³

References

1. U.S. Census Bureau, 2022 NAICS Manual (United States). https://www.census.gov/naics/reference_files_tools/2022_NAICS_Manual.pdf
2. General Services Administration, Product and Service Codes (PSC) Manual, April 2025. https://www.acquisition.gov/sites/default/files/manual/PSC%20Manual%20April%202025.pdf
3. U.S. Census Bureau, North American Industry Classification System (NAICS) main page. https://www.census.gov/naics