A welder is a tradesman who specialises in welding materials together. The materials to be joined can be metals (such as steel, aluminium, brass, stainless steel etc.) or varieties of plastic or polymer.
Welders typically have to have good dexterity and attention to detail. Depending upon the type of welding being undertaken, various safety precautions must be taken. Hazards caused by heat and flames are fairly obvious, the intense ultraviolet light produced by arc welding can cause serious eye injury (known as arc eye). The light can also cause burns to skin. Fumes given off by welding can cause respiratory problems, such as welders lung.