Welding under different circumstances, three classification methods: Classification of welding rod use classification, according to the classification of the main chemical ingredient of the drug skin, drug skin melting slag characteristics. There are two forms of expression in accordance with the purpose of the Aluminum Electrode, a former Ministry of Machinery Industry prepared, welding can be divided into: structural steel Aluminum Electrode, heat-resisting steel electrodes, stainless steel welding rod, welding electrodes, low temperature steel electrodes, cast iron electrode , nickel and nickel alloy rods, copper and copper alloys, aluminum and aluminum alloys and special purpose welding rod. National standards for carbon steel electrode, low alloy electrodes, stainless steel welding rod, welding electrodes, cast iron welding rod, copper and copper alloys, aluminum and aluminum alloys. Two there is no difference of principle, the former commercial grade, the latter model, said. Classified according to the chemical composition of the electrode drug skin, welding can be divided into: type electrode of titanium dioxide, titanium dioxide calcium electrode, ilmenite type electrode, the iron oxide type electrode, cellulose type electrode, low hydrogen type electrode graphite electrode and the base electrode. According to the melting of the electrode drug skin characteristics of the slag to classification, welding can be divided into acid electrode and alkaline welding rod. The main ingredient of the drug skin acid electrode for acidic oxides such as silica, titanium dioxide, ferric oxide, etc.. Alkaline electrode main ingredient of the drug skin as alkaline oxides, such as marble, fluorite. The classification of the welding rod, respectively, by end-use, the different perspectives of the slag basicity, the main component of the electrode drug skin, the electrode performance characteristics to classify the welding.