Samples of protective plates made by Defence Clothing. They are used in body armour and show the effect of ballistic testing. The plate on the left is made from steel. Although steel is very strong, this piece was not tough enough to stop a bullet flying straight through it. The plate on the right is made from a layer of alumina backed with several layers of aramid fibres and weighs les than the steel plate. It is inserted into a pocket in a flak jacket to provide extra protection to the heart. Both pieces were tested in exactly the same way.
© Science Museum / Science & Society Picture Library