Aluminium is a ductile, silvery-grey metal which is principally extracted from bauxite. It weighs around a third of steel or copper, precisely 2700 kg/m³. It’s malleable, ductile, durable, easily workable and has an excellent resistance to corrosion. In addition aluminium is non magnetic, doesn’t easily ignite and has a high thermal and electrical conductivity, around two thirds of that of copper while having 30% of copper’s density. Aluminium bars and tubes also have high plasticity, low emissivity and are also weldable using standard methods MIG, TIG and soldering (alloys containing copper are not weldable). Aluminium distinguishes itself from other metals due to its excellent resistance to corrosion which occurs because of the thin layer of aluminium oxide which forms when the metal is exposed to air protecting it from further oxidation anodising. The metal can also be coloured through electro colouring. Few natural elements can produce the high number of alloys that can be made with aluminium.