Spring washers are used in a variety of circumstances

Stainless Steel Bellevilles Stainless spring washers are one of the most common materials for disc springs. They usually have a standard coating that is suitable for most environments, allowing it to be corrosion resistant as well as highly durable. Because of their wide use, stainless spring washerscome in a variety of diameters and deflections without having to have them custom made for a specific project. Cold rolling and precipitation-hardening processes are often used to increase the corrosion resistance. These processes may also give the disc springs some magnetic properties. Some stainless steel or carbonized steel Belleville washers are classified as heavy duty spring washers. These washers are capable of handling higher axial loads than other types of spring washers. Heavy duty spring washers also reduce the dynamic loading of the screw because of its high elasticity. For this reason, it also is able to create a uniformly concentric loading pressure with high safety. This provides optimum compensation for setting in the joint of heavy loading parts. Rubber Spring Washers Rubber and silicone products are used for the sake of shock absorption and their ability to be compressed while retaining their elasticity. These materials can act as seals and 'pushers.' Rubber and silicone disc springs prevent harmful vibration from spreading to its connections, and for this reason, they may also reduce noise levels of an operating machine. These are often used in mountings and within computers. Aluminum, Nickel, and Zinc Disc Spring Coatings Aluminum and zinc are often used as coatings for disc springs to enhance certain qualities already present in the base metal. These compound coatings may increase a washer's electrical conductivity and corrosion resistance. Nickel can be used as a plating material to ensure a smooth and even finish. This plating also increases the corrosion resistance ability of the washer. Many of these coatings aim to eliminate corrosion as much as possible because rust or oxidization can harm the integrity of the washer. Oxidization makes a washer brittle, and a brittle washer may easily shatter if enough sudden pressure or constant vibrations are applied. A machine is only as strong as its weakest part, so a fragile connection will also harm the integrity of the machine as a whole. Copper Belleville Washers Both copper and aluminum disc springs are softer than steel washers. They are highly malleable and are good for making seals. Aluminum, being the softer of the metals, is better used in dirty seals because of its ability to conform more easily. However, because these materials are softer, there is a greater chance that they will mushroom out if too much torque is used on the washer.