Common materials for rubber washers include NBR (Nitrile Rubber), SBR (Styrene-Butadiene Rubber), HNBR (Hydrogenated Nitrile Rubber), EPDM (Ethylene Propylene Diene Monomer), Silicone, Viton (Fluoroelastomer), CR (Chloroprene Rubber), and FFKM (Perfluoroelastomer).
NBR is the most widely used material for rubber washers due to its excellent cost-performance ratio. In contrast, FFKM washers are typically used in high-end sectors, such as aerospace and rocketry; while they are quite expensive, their performance is exceptional-surpassing that of many metals.