With the development of mining industry, pig iron classification in Our country has been very extensive, can satisfy the demand of machinery industry. In general, iron used to produce large coils of galvanized wire can be divided into two classes. A metal produced directly from iron ore and iron smelting, consisting of iron oxide, silicon dioxide, and other miscellaneous stones. When this ore is specially refined into metal iron, carbon, silicon, manganese, and other elements are mixed in, so that the refined material is called general pig iron, is also for the initial grade of the material.

That said, it can always deform by pulling hard without changing its integrity, so cold drawing has usually reached a limit, which is not a problem, because without this property it increases hardness, which is the desired effect. Cold wire drawing encountered more rain, when the climate is wet, easy oxidation and rust. Therefore, in the storage process should pay attention to avoid rust.