The most widely used types of welding are stick or arc, gas metal arc, gas tungsten arc, plasma arc, shielded-metal arc, submerged arc, electroslag, flux-cored, metal inert gas and tungsten inert gas. The type of welding used usually depends on the thickness and form of the material.
Welding is the process of fusing two or more pieces of metal or thermoplastics by the use of heat and pressure. Arc welding is the most basic type of welding. It gets its name from the arc-shaped electrical current formed between the welding device and the material to be welded. The idea of welding came about in the Middle Ages, but the modern welding process did not exist until the later part of the 19th century.