Tinplate

Tinplate consists of sheets of steel coated with a thin layer of tin to impede rusting. Before the advent of cheap mild steel, the backing metal (known as "backplate") was wrought iron. While once more widely used, the primary use of tinplate now is the manufacture of tin cans.

In the tinning process, 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. Plates were once produced individually (or in small groups) in what became known as a pack mill. In the late 1920s pack mills began to be replaced by strip mills which produced larger quantities more economically.

Formerly, tinplate was used for tin ceiling, and holloware (cheap pots and pans), also known as tinware. The people who made tinware (metal spinning) were tinplate workers.

For many purposes, tinplate has been replaced by galvanised metal, the base being treated with a zinc coating. It is suitable in many applications where tinplate was formerly used, although not for cooking vessels, or in other high temperature situations—when heated, fumes from zinc oxide are given off; exposure to such gases can produce toxicity syndromes such as metal fume fever.[1] 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.

  1. ^ Bradberry, S. M.; Vale, J. A. (28 January 1998). "Zinc oxide (UK PID)". INCHEM. International Programme on Chemical Safety (IPCS); World Health Orgnization.