METALS There are two groups of metals: â€˘
Ferrous metals: These are iron (the pure metal) or alloys that contain iron : soft iron, steel, cast iron
Non-ferrous metals: do not contain iron. Example, copper tubes
Trey can be classified according to their density: Ultralight: Density less than 2kg/l. For example, magnesium. Light: Density between 2 and 5 kg. Aluminium and titanium are light. Heavy: Density superior to 5kg/l. All the other metals are heavy.