An electric arc furnace is a system, which heats charged material by means of an electric arc. Arc furnaces range in size from small units of approximately one ton capacity used in foundries for producing cast iron products, up to about 400 ton units used for secondary steelmaking. Arc furnaces used in research laboratories and by dentists may have a capacity of only a few dozen grams. Temperatures inside an electric arc furnace can rise to approximately 1,800 degrees Celsius. It allows direct melting of raw steel and uses less energy than fossil-fired furnaces.