A qualification test is given to welders when they are hired. This assessment tests the skills of the welders by showing off their work. There are many types of certifications based upon the type of welding that is done. For instance, G on a 4-G level stands for groove welding. Fillets are another type of weld that is looked at in the qualification test. These are represented by Fs. A welder must be able to read schematics and drawings, change out empty gas tanks, and use other equipment like sanders and grinders. A welder should also know about different metals (copper, steel, and aluminum), wire, sheet metal, and filler rods. Certifications and licenses can further a welder’s revenue and can be learned at schools or the workplace. There are many types of welding schools located all over the U.S. Scholarships are given to pupils based on the type of welding being taught. Once a person goes to school they can choose to be hired under an apprenticeship. An apprenticeship can last 4-5 years and can be paid for by the company. There are unions designated specifically to welders.