NAICS 333613

Overview

The North American Industry Classification System (NAICS) is the federal standard for classifying business establishments to support the collection, analysis, and publication of statistics on the U.S. economy. Developed under the Office of Management and Budget and adopted in 1997 to replace the SIC system, NAICS is jointly maintained with Canada and Mexico and is currently published in its 2022 vintage. ¹

U.S. industry NAICS code 333613 covers establishments primarily engaged in manufacturing mechanical power transmission equipment not for motor vehicles or aircraft. Examples include plain bearings; mechanical (non-vehicle, non-electromagnetic) clutches and brakes; couplings and universal joints; and drive chains. Federal statistical programs use this code to tabulate manufacturing activity within the machinery domain and to benchmark related economic indicators. ²

See also on G2X:

• G2X — NAICS 333613 overview
• G2X — NAICS 333612
• G2X — NAICS 336350

What this NAICS covers

• Manufacturing of plain bearings and bushings for mechanical power transmission (non-engine). ²
• Manufacturing of mechanical clutches and brakes (excluding motor vehicle and electromagnetic industrial control). ²
• Manufacturing of shaft couplings, universal joints, and related connectors (except aircraft and motor-vehicle uses). ²
• Manufacturing of drive chains, sprocket-type chains, and associated transmission chain components. ²
• Manufacturing of power transmission pulleys and similar motion-transfer components (non-vehicle, non-aircraft). ²
• Manufacturing of assembled mechanical power transmission sub-systems for industrial equipment. ²

Related NAICS and PSC codes

Cross-references and exclusions (how Census classifies borderline work)

• Motor-vehicle power transmission equipment is classified in NAICS 336350, not in 333613. ²
• Aircraft power transmission equipment is classified in NAICS 336413, not in 333613. ²
• Gears, speed changers, and industrial high-speed drives belong in NAICS 333612, not in 333613. ²

2022 NAICS vintage notes

NAICS is reviewed and revised every five years. The Census Bureau began publishing statistics on the 2022 NAICS basis with the 2022 Economic Census and plans full adoption across economic programs by the end of calendar year 2027; program-specific change lists document any code-level revisions between 2017 and 2022. ³

Frequently asked questions

• What products fall under NAICS 333613? Mechanical power transmission components such as plain bearings, mechanical clutches and brakes, couplings, universal joints, pulleys, and drive chains are in scope, provided they are not for motor vehicles or aircraft and are not electromagnetic control devices. These items support motion and torque transfer in industrial machinery. ²

• What products are excluded from NAICS 333613? Equipment designed for motor vehicles and aircraft is classified under NAICS 336350 and 336413, respectively. Gears, speed changers, and industrial high-speed drives fall under NAICS 333612, not 333613. These exclusions help separate vehicle and aerospace supply chains from general machinery. ²

• Did NAICS 333613 change in the 2022 update? The 2022 revision introduced adjustments across multiple sectors and provides an official “2017 to 2022 NAICS Changes” list. Users should verify any impacts on 333613 in that list. Code-specific revisions for 333613 are not summarized on the overview page. Not specified by official sources. ³

• How is NAICS 333613 used in federal statistics? The Economic Census and related programs publish manufacturing data by NAICS, including sector 31–33 and detailed six-digit industries like 333613. These data inform benchmarking, input-output accounts, and program evaluation, and are used by agencies, researchers, and industry to assess market size and trends. ⁴

• Which PSCs commonly align with mechanical power transmission items? Agencies often use PSC class 3020 for gears, pulleys, sprockets, and transmission chain when buying supplies related to mechanical power transmission. For authoritative scope notes and cross-walks, consult the current Product and Service Code (PSC) Manual maintained on Acquisition.gov. ⁵

Useful resources

• G2X — NAICS 333613
• Census NAICS definition for 333613 (Sector 31–33 archive page). ²
• Census: Implementation of the 2022 NAICS (timeline, change list). ³
• Census: 2022 Economic Census — Manufacturing sector (NAICS 31–33) resources. ⁴
• GSA Acquisition.gov: Product and Service Code (PSC) Manual (current edition). ⁵

References

1. U.S. Census Bureau, 2017 North American Industry Classification System (NAICS) Manual. https://www.census.gov/library/publications/2017/econ/2017-naics-manual.html
2. U.S. Census Bureau, NAICS Sector 31–33 — Manufacturing (includes definition and cross-references for 333613). https://www.census.gov/naics/resources/archives/sect31-33.html
3. U.S. Census Bureau, The Census Bureau’s Implementation of the 2022 NAICS (timeline and 2017→2022 changes). https://www.census.gov/library/reference/code-lists/naics/2022/implementation-timeline.html
4. U.S. Census Bureau, 2022 NAICS Sector 31–33 — Manufacturing (Economic Census tables/resources). https://www.census.gov/data/tables/2022/econ/economic-census/naics-sector-31-33.html
5. General Services Administration, Product and Service Code Manual (current). https://www.acquisition.gov/psc-manual/all