Coated on the surface of the active ingredient of the welding heart known as the drug skin, also called coating. Its main ingredient is organic and chemical products of: ore powder ferroalloy powder! Is not a simple metal powder! The drug skin's main role is to: protect the weld pool add useful elements to ensure removal of harmful substances arc easy ignition and sustained combustion to reduce spatter weld appearance! Works for arc welding: welding electrode end weldment produce the 6000-7000 degree arc column weld heart iron bar drug skin weldment melt the solder heart end formation tiny metal droplet spray in the melt through the arc column the surface of the weldment drug skin to play its role in the melting and solidification! Drug skin and welding heart female member of a series of physical and chemical reactions that occur in the energy generated by welding and can not meet the heat required can be said welding all of the required heat energy from the electricity!