The sale of reusable salvage from old cars is only a small piece of the auto recycling pie. Once cars are crushed, they're shipped off to a recycling center where they are shredded and separated into small pieces, which are then sorted into various metals.

Metals can be classified as ferrous, or non-ferrous. Ferrous metals are combinations of iron with carbon. Some common ferrous metals include carbon steel, alloy steel, wrought iron, and cast iron. On the other hand, non-ferrous metals include aluminum, copper, lead, zinc, and tin. Precious metals are non-ferrous. The most common precious metals inc