Neoprene—If you're not sure which material best suits your needs, these versatile washers are a great solution. They offer a good balance of strength and flexibility to hold a tight seal, even in wet and outdoor conditions. These washers also withstand salt water and mild chemicals, such as detergents. However, they don't resist oil, grease, or fuel as well as Buna-N washers.

Oil-Resistant Buna-N—With the best oil resistance of all our rubber washers, these won't swell or soften when they touch oil, grease, or fuel. However, they will break down if exposed to synthetic lubricants.

Oil-Resistant Aramid-Reinforced Buna-N—These washers are embedded with aramid, which is the same material used in bulletproof vests. This addition makes them stronger and more heat resistant than standard Buna-N washers for a longer lifespan. They won't degrade when exposed to oil, grease, and fuel.

Weather-Resistant EPDM—The best choice for outdoor use, these washers withstand long-term exposure to sunlight, rain, and ozone. However, they can't handle oil, grease, or fuel like Buna-N washers can.

Weather- and Chemical-Resistant Santoprene—Not only will these washers withstand sunlight, rain, and ozone, they also won't degrade when exposed to acids and other harsh chemicals. They are more wear resistant than EPDM washers to stand up to repeated use.

Chemical-Resistant Fluoroelastomer—The best chemical resistance of all our rubber washers. These withstand oil, grease, fuel, solvents, synthetic lubricants, and acids, even at high temperatures. They are also stiffer than other rubber washers, so they are better at distributing weight.

High-Temperature Silicone—Withstand the widest temperature range of all our rubber washers. They resist detergents but will break down when exposed to oil, grease, and fuel.

High-Temperature Chemical-Resistant Fluorosilicone—These washers handle a similar temperature range as silicone and are nearly as chemical resistant as fluoroelastomer. Commonly used in the aerospace industry, they withstand oil, grease, and fuel.

Cork/Neoprene—Combine the cushioning of cork with the durability of rubber. These washers dampen vibration and noise in rattling assemblies while maintaining a strong seal.