They usually have a triangular or trapezoidal cross-section and are reinforced with fiberglass, polyester, or steel. V-ribbed pulleys are made from materials such as aluminum, brass, cast iron, steel, ...

Aluminum is lighter and less strong than steel, a form of iron that contains carbon in any amount up to about 1.7 percent as an essential alloying constituent. Many grades of carbon and alloy steels ...