O-rings are generally made of synthetic rubber although special o-rings may also be constructed from thermoset materials such as silicone. They’re most common in the automotive and machine manufacturing industries for which they serve a wide variety of sealing applications. Silicone O-rings are a type of seal that is commonly used in a variety of industrial and consumer applications. They are made from silicone, a synthetic rubber that is known for its excellent heat resistance, chemical resistance, and flexibility. Silicone O-rings are often used as seals in high-temperature environments, such as in engines or in industrial equipment that operates at high temperatures. They are also commonly used in applications where chemical resistance is important, such as in the chemical and pharmaceutical industries. Silicone O-rings are typically more expensive than other types of O-rings, but their superior performance in demanding environments often justifies the added cost.