O-rings are used to block openings and prevent liquids or gases from escaping in appliances and machines. While O-rings can be made of any number of materials, rubber is the most common due to its durability, hardness, and heat resistance. Review this brief guide to learn about the different types of rubber O-ring materials.

A Guide to Rubber O-Ring Materials

1. Ethylene Propylene Diene Monomer (EPDM)

Ethylene propylene diene monomer (EPDM) is a type of versatile synthetic rubber. It can withstand a wide range of temperatures, from -60 degrees to 300 degrees. This makes it ideal for a variety of applications, including appliance, automotive, medical device, and wastewater system manufacturing. On the durometer scale of hardness, EPDM has a rating of 40 to 90.

2. Nitrite

Nitrite, which is also a synthetic rubber, can operate in temperatures from -40 degrees to 250 degrees. As known as Buna-N, it has the same hardness rating as EPDM.

Because natural rubber can react with fuel, oil, and similar chemicals, nitrite O-rings are widely utilized in the production of fuel tanks and other automotive and aerospace parts. These products are also commonly found in pumps, hydraulic equipment, and fluid pressurizing applications. 

3. Silicone

Silicone is an umbrella term used to describe several different polymers, one of which is silicone rubber. This material is prized for its stability and nonreactivity. It can function in temperatures from -75 degrees to 450 degrees, and it has a hardness rating of 30 to 80.

You'll find silicone rubber in many static applications, especially those that utilize dry heat, like certain automotive, food storage, and electronic components. Silicone rubber is generally not used in products that deal with acids, brake fluids, or other harsh chemicals.

When you need rubber O-rings for an upcoming project, contact Rothkopf. Since 1956, they've served customers throughout Chesterfield, MO. They provide a wide selection of molded rubber products, including O-rings, U-cups, gaskets, diaphragms, and oil seals. They offer both premade parts and custom-made items manufactured to the specifications of your project. Call (636) 449-2366 or visit their website to learn more about their selection.