Welder definition
A welder is a skilled tradesperson who permanently joins metal components by applying heat sufficient to melt the base materials, typically with the addition of a filler metal, creating a metallurgical bond. Welders work across virtually every industrial sector — construction, manufacturing, oil and gas, power generation, aerospace, automotive, and shipbuilding — making it one of the most broadly employed skilled trades in the US economy.
The Bureau of Labor Statistics classifies welders, cutters, solderers, and brazers under SOC code 51-4121, with approximately 430,000 workers employed in the US. However, industrial welders — particularly those with ASME, AWS, or API certifications working in refinery, power generation, and construction environments — represent a more specialized and higher-compensated segment of this broader category.
What are the main welding processes?
| Process | Common Name | Primary Application |
|---|---|---|
| GMAW (Gas Metal Arc Welding) | MIG Welding | Manufacturing, fabrication, thin to medium gauge |
| SMAW (Shielded Metal Arc Welding) | Stick Welding | Construction, maintenance, outdoor field work |
| GTAW (Gas Tungsten Arc Welding) | TIG Welding | Aerospace, pipe root passes, stainless steel, aluminum |
| FCAW (Flux-Cored Arc Welding) | Wire Welding | Structural steel, shipbuilding, heavy fabrication |
| SAW (Submerged Arc Welding) | Sub-Arc | Heavy plate, pipeline, pressure vessel fabrication |
What certifications do welders hold?
- AWS D1.1 (Structural Steel Welding): The baseline certification for structural steel work — buildings, bridges, and industrial frameworks. Tests specific positions and processes under the American Welding Society D1.1 code.
- ASME Section IX: Procedure and performance qualification for pressure-containing welds — boilers, pressure vessels, and process piping. Required for refinery, power generation, and chemical plant welding work.
- API 1104 (Pipeline Welding): Certification for oil, gas, and water pipeline welding. Governs field girth welds on transmission pipelines.
- AWS D1.8 (Seismic Supplement): Additional qualification for structural welding in seismic zones. Required on moment frame connections in California and other high-seismic markets.
For a complete breakdown of certifications by application, see the welding certifications glossary. For compensation data by certification level, see the welder salary guide.
What industries employ welders?
| Industry | Welder Types Employed | Key Markets |
|---|---|---|
| Petroleum Refining | ASME, API certified pipe welders | Texas, Louisiana, California |
| Structural Construction | AWS D1.1 structural welders | Nationwide; NYC, Chicago, LA top markets |
| Aerospace / Defense | GTAW specialists, MIL-SPEC qualified | California, Texas, Washington, Florida |
| Automotive Manufacturing | GMAW, robotic welding technicians | Michigan, Indiana, Ohio, Kentucky |
| Power Generation | ASME Section I and IX welders | Nationwide |
| Shipbuilding and Marine | FCAW, SMAW multi-process | Gulf Coast, Pacific Coast, Chesapeake |
For marketing guidance for agencies placing welders, see welder staffing agency SEO. For hiring guidance for clients, see how to hire certified welders.