A wire brush is a tool consisting of bristles made of wire, most often steel wire. The steel used is generally a high carbon variety and very hard. The wire brush is used for cleaning metal surfaces by removing rust, paint, or other debris. It can also be used to create a rough surface on softer metals like aluminum or brass. When using a wire brush on wood, it is important to choose one with softer bristles, as theharder bristles can damage the wood.