Iron is hard, brittle and has a fairly low melting point (fusible). It is found in a variety of alloys, known as 'ferrous metals'. These are cast iron, wrought iron and steel. Iron sheet is also galvanized or tin-plated. All these metals are attracted by a magnet.
Cast iron is an alloy of iron containing so much carbon that it is brittle; it must be shaped by casting. Depending on how the carbon is combined with the iron, the colour varies; for example there is 'white iron' or 'grey iron'.
Wrought iron is a very pure form of iron with only about half of one per cent carbon. It is tough, malleable, less fusible, and usually has a fibrous structure.
Carbon steel is an alloy of iron with small amounts of other minerals.
Iron can also be enameled, as in a bath, to prevent corrosion and giving a smooth, decorative surface.
Cast iron is encountered in older houses in rainwater goods (guttering, downpipes), waste pipes, in fire grates and ranges. Cast iron was also used for baths, fencing, gates, for gas pipes, and in some door furniture.
Wrought iron is less common but used for some fencing.
Steel is used in door fittings and some pipework.
Even iron can be toxic; this danger is higher for sufferers of cirrhosis of the liver or if alcoholic or acidic drinks are consumed by a worker contaminated with ferrous dust.
Painted iron and steel can be stripped with standard chemical stripper.
Remove dirt with methylated spirit or paraffin; soak it for 24 hours and then rub with fine wire wool.
Dry the metal, apply a rust protector, primer and then paint. Use a calcium-plumbate or zinc-phosphate primer, and then a semi-matt black paint. Alternatively, just rub the metal occasionally with an oily rag. The traditional treatment for cast iron grates was Zebrite; modern alternatives are available from fireplace shops.