The O-ring, introduced in the late 19th century and officially patented in the United States in the 1930s, immediately sparked interest in the potential of its design. Soon, designers incorporated the O-ring into devices such as engines, pumps, and pipe joints. Over a century later, the O-ring is now the most commonly used seal in the world. 

The core form and function of the O-ring have remained the same, but technological developments have improved O-ring seal applications and options. 

There are different material and size options to suit any device’s specifications. At Wyatt Seal, we offer a wide range of material options and custom sealing solutions.

What is an O-Ring?

It is important to understand what O-rings are and why they are such a popular seal choice. An O-ring is a round, donut-shaped object that is used to create a seal between two surfaces in a highly pressurized environment. When installed correctly, an O-ring seal can prevent nearly all fluids from escaping containers in both liquid and gaseous states. 

The material of O-rings depends on their application, but common materials for O-rings include nitrile, HNBR, fluorocarbon, EPDM, and silicone. O-rings also come in various sizes since they must be fitted precisely to function correctly. These seals are called O-rings because of their circular or “O-shaped” cross-section. The shape of the O-ring stays consistent, but the size and material are customizable.

How do O-Rings Work?

O-rings are used for sealing components in high-pressure applications where their unique resistance to pressure and maintaining shape are essential. O-ring seals are installed into the space between two components or surfaces that are placed together. For example, O-rings are placed between the grooves in two components of a pump. 

Once installed, the O-ring seal remains in place and is compressed in the joint, forming a tight, sturdy seal. With proper installation, material, and size, the O-ring can withstand internal pressure and prevent any fluid from escaping. 

O-rings may warp under too much pressure if installed incorrectly or if they are not the proper size or material. However, O-rings can withstand significant pressure in the right conditions. Most standard O-rings are designed to function at pressures up to 1500 psi.  O-ring suppliers are able to provide designs that can operate at higher pressures when necessary. 

Common Uses 

O-rings can be applied to any device or machinery with components that require secure sealing. Common applications include devices like vehicle engines, fuel pumps, valves, storage tanks, and more. These broad applications leave potential for a variety of industries to benefit from O-ring seals. O-rings are commonly used in the following industries: 


Industrial applications offer a range of uses for O-ring seals. O-rings are commonly used in factory machinery, fuel and chemical processing, and more to prevent leaking and ensure maximum efficiency. 

Life Sciences:

Life sciences, which includes labs and the medical field, use O-ring seals within equipment like syringes, pumps, and filtration devices. O-rings prevent the cross-contamination of fluids and prevent leakage. 

Oil & Gas/ Energy

The energy sector, including oil and gas companies, use O-rings in storage tanks, pumps, valves, and piping. The O-ring seals in this industry must prevent hazardous chemicals from leaking. O-rings in this field must also withstand extreme pressures, temperatures, and harsh chemicals. 

Fluid Power:

Fluid power systems, like hydraulic systems, transfer fluid from one location to another to generate power. O-ring seals increase power efficiency by preventing fluid loss. 

Chemical Processing:

Chemical processing systems handle hazardous chemicals that can be dangerous to employees and the environment. Secure O-ring seals are essential to prevent spillage and leaking. 

Heavy Equipment:

Heavy equipment references a range of vehicles and tools, like automobiles, construction equipment, and power tools. O-ring seals are necessary in heavy equipment to facilitate pressure in combustion chambers and to prevent fuel leakage. 

O-Ring Materials

An O-ring’s reliability is directly related to proper installation and appropriately chosen materials. When selecting the O-ring that will suit your project’s needs, it is important to consult professionals and explore all material options.

Wyatt Seal’s sealing products include a variety of O-ring options to ensure that every project finds a functional and secure sealing solution. 

Popular O-ring material options include: 

Often O-ring seals are color-coded to correspond to their material. Color coding is available and can simplify the installation process, but you should never assume that color tells you the material of a previously existing O-ring. 


Since O-ring sizing requires precision, O-rings have two identifying measurements: the inside diameter (ID) and the cross-section (CS). The inside diameter is found by measuring the inside of the O-ring, from inside wall to inside wall. The cross-section measurement is found by measuring the width of one side of the O-ring. This could also be defined as the height of the O-ring when it lies on a flat surface.  Check out our o-ring size chart for more information.

As an O-ring supplier, we understand the importance of caution and precision in the decision-making process. We offer custom solutions to ensure that your O-ring seals have high durability and longevity. Wyatt Seal is proud to offer a variety of Parker O-Rings, Kalrez® o-rings and custom o-rings to support every project’s unique needs.

Are you ready to find the perfect O-ring seal for your application? Reach out to one of our sealing experts today.