The difference between ferrous and non-ferrous metals is that ferrous metals contain iron and non-ferrous metals do not. This basic difference imparts distinctive properties on the two types of metals, which add to their own personal physical properties and determine the applications they are most suited for.
Washers are made from a variety of materials, the most popular of which are galvanized carbon steel and stainless steel. Carbon steel is stronger than stainless steel, but stainless steel will not rust or corrode like carbon steel can. Other metal washers include zinc, copper, brass and iron.
Metal washers are thin, disk-shaped plates with a hole that distributes the load of a screw, nut, or other threaded fastener. They can be manufactured for a variety of purposes and product requirements in industrial applications.