Are circular in shape, no wider than 2”, standard brushes range from 1” to 16” in diameter. These may be filled with materials such as carbon steel, stainless steel, brass, bronze and natural fibers such as tampico.  Also available in standard and custom made with both abrasive and non-abrasive nylon and polypropylene.  There are two basic types of wire used in wheel brushes – crimped wire for flexibility and straight wire (knot type) for more aggressive brushing.