A wire brush is a tool, consisting of a handle, usually wood or plastic, occasionally bone, and a brush. The brush is usually made from a large number of steel wire bristles. The steel used is generally a high carbon variety and very hard. Other wire brushes feature bristles made from brass or stainless steel, depending on application. Wires in a wire brush can be held together by epoxy, staples, or in some cases one continuous wire. Some types of wire brushes can also be used on an angle grinder or electric drill.