The coating of steel or iron with zinc. Generally by immersion in a bath or molten zinc, covered with flux at a temperature of between 425°C and 500°C. The zinc may alternatively be electrodeposited from cold zinc sulphate solutions. The zinc is capable of protecting iron from atmospheric corrosion even when the coating is scratched since the zinc is preferentially attacked by acidic rain (carbonic acid), forming a protective coating of basic zinc carbonates.