Aluminium is widely used in the engineering industry. Aluminium is lightweight but very strong and it has a very good strength to weight ratio. Aluminium alloys provide strong resistance to atmospheric corrosion in many different environmental settings. This is particularly useful for large structures or for marine applications where seawater is a constant threat. Aluminium structures and equipment have a longer lifespan and require less maintenance than many competing materials. With the additional surface treatments available, aluminium can offer life long use with very little maintenance requirements.