Hot-dip galvanizing

Hot-dip galvanizing is a form of zinc layer, by passing the steel through a molten bath of zinc at a temperature of around 860 °F (460 °C). When exposed to the atmosphere, pure zinc reacts with oxygen to form zinc oxide, which further reacts with carbon dioxide to form zinc carbonate, a dull grey, fairly strong material that stops further corrosion in many circumstances, protecting the steel below from the elements. Galvanized steel is widely used in applications where rust resistance is needed, and can be identified by the crystallization patterning on the surface (often called a "spangle").