How to Tell the Differences in Metals

Lift a metal item with your hands to see how much weight it has. The weight of metal tells you a lot about its composition. Steel is one of the heaviest metals, and will feel substantial and may take some effort to lift. Aluminum is known for its lightweight properties. Generally, it will be easy to lift and hold. Brass is also lighter in weight. Alloys can contain any number of different metals bound together chemically, so the weight test does not tell you as much as with single composition metals.

Examine the metal visually. If unpainted or unfinished, you can determine quite a bit about the composition of a metal. Steel is generally grayish or darkened to black. It may have pitting, discolorations and rusted areas. Stainless steel is a mixture of different metals, including nickel. It has a high shine and an even silver appearance. Aluminum is also silver-colored, but has a duller appearance and may have whitish areas where it has oxidized. Brass, often used for decorative items, has a bright, gold-colored shine and may have a protective coating of lacquer.

Test the strength of the metal. Try to bend or dent it by tapping it gently with a hammer. Steel is very strong and resists bending and gouging. Aluminum is a soft metal that is known for its flexibility. It will tend to bend easily and will show marks with little effort. Brass is also soft and will show scratches quite clearly. Alloy metals vary in strength, but often contain steel so these metals will be durable and rigid.