A light metal is any
metal of relatively low density.[1] More specific definitions have been proposed; none have obtained widespread acceptance.
Magnesium,
aluminium and
titanium are light metals of significant commercial importance.[2] Their densities of 1.7, 2.7 and 4.5 g/cm3 range from 19 to 56% of the densities of the older structural metals,[3]iron (7.9) and
copper (8.9).