Shop hard facing arc electrodes. Hardfacing is the process of using arc welding to lay a wear-resistant metal over parts that are exposed to abrasives, friction or impact. The material is a hardened steel alloy that serves as a sacrificial layer to prevent more serious wear on the tool itself, the cutting edges of excavators, bulldozer blades and rock drills, for example. Hardfacing is also carried out for steel track rollers, drive sprocket teeth and valve seats and faces.