Polyurethane O-rings

O-RINGS

Polyurethane, commonly abbreviated as AU, is a versatile, durable polymer valued in sealing applications for its exceptional abrasion resistance, high tensile strength, and ability to perform under heavy loads. In the sealing industry, polyurethane is often referred to simply as “urethane,” though both terms describe the same high-performance material. Unlike many elastomers, urethane O-rings combine flexibility with outstanding wear resistance, making them ideal for both static and dynamic applications. They offer excellent resistance to oils, fuels, and many solvents, as well as strong resilience against tearing and extrusion under pressure.

Urethane seals are widely used in industries such as hydraulics, pneumatics, automotive, construction, and material handling—particularly in applications where impact resistance, load-bearing capacity, and long service life are essential.

Features and Specifications

Temperature Range

Standard polyurethane O-ring temperature ranges are from -65 °F (-54 °C) to 212 °F (100 °C), with some specialized formulations capable of withstanding higher temperatures for short durations.

Durometer

Standard durometer (hardness) can range from 60 Shore A to 95 Shore A, with the standard typically being 90 Shore A. This range provides a balance of flexibility, wear resistance, and load-bearing capability, making polyurethane seals suitable for both dynamic and static applications.

Color

Urethane O-rings are most commonly semi-translucent yellow in color. However, they can be made in alternative colors for applications where high visibility is needed.

Benefits of Polyurethane O-rings

Polyurethane seals are highly valued for their excellent mechanical strength, abrasion resistance, and resilience, making them a reliable choice for demanding sealing applications across industries such as hydraulics, automotive, construction, and manufacturing. Known for their outstanding wear resistance and ability to maintain flexibility under pressure, urethane seals deliver consistent performance even in high-load and high-cycle environments. They combine good hydrolytic stability, resistance to tearing and extrusion, and strong sealing capabilities, making them ideal for applications requiring long-lasting, leak-free operation. Urethane seals offer several beneficial mechanical properties, including:

  • Chemical resistance
  • Flexibility
  • High load-bearing capacity
  • Low compression set
  • Resistance to aging and sunlight
  • Tensile strength and tear resistance

Additionally, polyurethane O-rings are resistant to:

  • Abrasions
  • Cleaning agents
  • Diluted alkalis
  • Grease 
  • High impact
  • Mold
  • Oxidation
  • Sunlight 
  • Water
  • Weather

Common Uses and Applications of Polyurethane O-rings

Urethane seals are well-suited for a wide range of static and dynamic applications, offering excellent durability and mechanical performance in demanding operating environments. Known for their high wear resistance, load-bearing capacity, and flexibility, urethane seals can be custom-molded into specialized shapes and sizes to meet unique design requirements while maintaining long-lasting, leak-free sealing. They are commonly used in industries such as automotive, hydraulics, oil and gas, marine, and construction—particularly in systems exposed to high pressure, abrasion, and mechanical stress. Typical applications include pumps, cylinders, valves, and heavy-duty machinery. Industries which utilize polyurethane O-rings include:

The wyatt seal advantage

We're here to help in selecting the right sealing solution. Tell us your specifications, and we'll partner with you to find the ideal O-rings for your next project. Contact Wyatt Seal to find out more about our O-ring selection and custom solutions.