A certified welder is has a certification from the American Welding Society (AWS). This is a voluntary certification for working welders that proves your ability. As a certified welder, you perform welding projects to a client’s specifications. You must understand the details of different welding metals, including stainless steel, aluminum, and brass. Additional job duties depend on your specific industry, whether that’s automobile manufacturing, construction, or maritime. You must be able to read blueprints and follow technical instructions.