Steel Tin Metal Formed Parts
Steel tin metal formed parts consists of sheets of steel, coated with a thin layer of tin. Before the advent of cheap milled steel, the backing metal was iron. While once more widely used, the primary use of tinplate now is the manufacture of tin cans. Tinplate has the strength and formability of steel combined with the noncorrosive and nontoxic properties of tin and has the additional property of easy solderability.
Tinplate is made by rolling the steel (or formerly iron) in a rolling mill, removing any mill scale by pickling it in acid, and then coating it with a thin layer of tin. For many purposes, tinplate has been replaced by galvanized (zinc-coated) vessels, though not for cooking as zinc is poisonous. The zinc layer prevents the iron from rusting through sacrificial protection with the zinc oxidizing instead of the iron, whereas tin will only protect the iron if the tin surface remains unbroken.