The use of EAF electric arc furnace including DC electric arc furnace allows steel to be made from a 100% scrap metal feedstock, commonly known as 'cold ferrous feed' to emphases the fact that for an EAF, scrap is a regulated feed material.The primary benefit of this is the large reduction in specific energy (energy per unit weight) required to produce the steel. Another benefit is flexibility: while the electric blast furnace cannot vary their production by much and are never stopped, EAFs can be rapidly started and stopped,allowing the EAF steel mill to vary production according to demand. Although steelmaking arc furnaces generally use scraps steel as their primary eedstock, if hot metal from a blast furnace or direct-reduced iron is available economically, these can also be used as furnace feed.