NAICS 423840

Overview

The North American Industry Classification System (NAICS) is the federal standard for classifying business establishments so statistical agencies can collect, analyze, and publish data on the U.S. economy. Developed under OMB’s Economic Classification Policy Committee with Statistics Canada and Mexico’s INEGI, NAICS replaced SIC in 1997 and is updated on a five-year cycle; the current vintage is 2022. ¹

NAICS 423840 covers Industrial Supplies Merchant Wholesalers—establishments primarily engaged in wholesaling supplies used with machinery and equipment in manufacturing, oilfield, and warehousing activities. Illustrative examples include industrial containers, industrial diamonds, printing inks, gas-welding supplies (excluding gases), nonplumbing valves and fittings, and refractory materials. ²

What this NAICS covers

• Industrial containers and general industrial supplies distribution to business customers. ²
• Nonplumbing industrial valves and fittings wholesaling (excluding plumbing, heating, hydraulic, and pneumatic types). ²
• Gas-welding supplies wholesaling, excluding the gases themselves. ²
• Printing inks wholesaling as a representative industrial supply line. ²
• Refractory materials (e.g., bricks, blocks, shapes) wholesaling to industrial users. ²
• Industrial diamonds wholesaling for manufacturing uses. ²

Related NAICS and PSC codes

Type	Code	Descriptor
NAICS	423830	Industrial Machinery and Equipment Merchant Wholesalers
NAICS	423850	Service Establishment Equipment and Supplies Merchant Wholesalers
NAICS	423720	Plumbing and Heating Equipment and Supplies (Hydronics) Merchant Wholesalers
NAICS	424690	Other Chemical and Allied Products Merchant Wholesalers

Common exclusions and cross‑references

• Welding gases are not included in 423840; industrial gases distribution is classified under 424690. ²
• Plumbing and heating valves and fittings are classified in 423720, not in 423840. ²
• Paper or paperboard containers and related disposable plastic products fall under 424130, not 423840. ⁶
• Welding equipment itself (e.g., machines) is classified with industrial machinery wholesalers (e.g., 423830), outside 423840. ⁷

Data availability for this industry

• The 2022 Economic Census publishes NAICS 2022 statistics for Wholesale Trade (Sector 42), including data accessible via Sector 42 tables and FTP files. ³
• The Annual Wholesale Trade Survey (AWTS) produces national estimates by 2‑ to 4‑digit NAICS codes for merchant wholesalers, providing context for trends affecting 423840. ⁴

Frequently asked questions

• What businesses fit under NAICS 423840?
  Establishments primarily engaged in wholesaling industrial supplies used with machinery and equipment for manufacturing, oilfield, and warehousing operations. Examples include industrial containers, industrial diamonds, printing inks, gas‑welding supplies (except gases), nonplumbing valves and fittings, and refractories. ²

• How is NAICS 423840 different from 423830?
  423840 focuses on consumable and maintenance industrial supplies, whereas 423830 covers wholesaling of industrial machinery and equipment. The latter includes items like machine tools and related equipment, not consumable supplies. ⁷

• Are welding gases included in NAICS 423840?
  No. 423840 includes gas‑welding supplies other than the gases themselves. Industrial gases wholesaling is classified under chemical and allied products wholesalers, notably 424690. ²

• Which federal datasets commonly report on NAICS 423840 activity?
  The Annual Wholesale Trade Survey reports national estimates for 2‑ to 4‑digit NAICS groups and provides year‑over‑year trend indicators. Results for Wholesale Trade complement Economic Census benchmarks for Sector 42. ⁴

• What is the SBA small business size standard for NAICS 423840?
  SBA publishes size standards by NAICS. Wholesale Trade standards often use employee‑based thresholds, with definitive values set in SBA’s Table of Size Standards. Always consult the current table for the authoritative threshold. ⁵

Useful resources

• G2X — NAICS 423840
• Census — 2022 NAICS Sector 42: Wholesale Trade (Economic Census data tables and FTP). ³
• Census — NAICS Codes & Understanding Industry Classification Systems. ¹
• Census — 2022 Annual Wholesale Trade Survey (AWTS) release. ⁴

References

1. U.S. Census Bureau, Economic Census: NAICS Codes & Understanding Industry Classification Systems. https://www.census.gov/programs-surveys/economic-census/year/2022/guidance/understanding-naics.html
2. U.S. Census Bureau, 2022 NAICS Definition for 423840 — Industrial Supplies Merchant Wholesalers. https://www.census.gov/naics/?input=423840&year=2022&details=423840
3. U.S. Census Bureau, 2022 NAICS Sector 42 — Wholesale Trade (Economic Census). https://www.census.gov/data/tables/2022/econ/economic-census/naics-sector-42.html
4. U.S. Census Bureau, 2022 Annual Wholesale Trade Survey (AWTS) news release. https://www.census.gov/newsroom/press-releases/2024/annual-wholesale-trade-survey.html
5. U.S. Small Business Administration, Table of Size Standards. https://www.sba.gov/document/support/object-object-table-size-standards
6. U.S. Census Bureau, 2022 NAICS Definition for 424130 — Industrial and Personal Service Paper Merchant Wholesalers. https://www.census.gov/naics/?input=424130&year=2022&details=424130
7. U.S. Census Bureau, 2022 NAICS Definition for 423830 — Industrial Machinery and Equipment Merchant Wholesalers. https://www.census.gov/naics/?input=423830&year=2022&details=423830