HNBR O-rings

O-RINGS

Hydrogenated nitrile butadiene rubber, commonly abbreviated as HNBR, is a durable and versatile sealing material prized for its enhanced resistance to heat, chemicals, and mechanical stress. HNBR O-rings are made by hydrogenating nitrile butadiene rubber (NBR)—a process that infuses hydrogen into the polymer’s double bonds until they are fully saturated. This hydrogenation strengthens the polymer’s molecular structure, significantly improving durability and abrasion resistance.

As a result, HNBR O-rings deliver superior resistance to ozone, heat, chemicals, and mechanical wear compared to standard nitrile rubber. Their robust performance makes them an increasingly popular, cost-effective choice for engineers seeking reliable seals in demanding environments.

Widely used in industries like automotive, oil and gas, and industrial machinery, HNBR O-rings excel in applications requiring long-lasting, resilient seals exposed to heat, fuels, lubricants, and harsh chemicals.

Features and Specifications

Temperature Range

HNBR O-rings typically perform reliably within a temperature range of approximately -40°F (-40°C) up to 300°F (150°C), making them well-suited for many applications. Their hydrogenated nitrile structure offers enhanced thermal stability and resistance to aging, helping them maintain sealing integrity where standard nitrile rubbers might fail.

Durometer

HNBR O-rings typically come in a  durometer range of 70 Shore A to 90 Shore A, with 90 Shore A being the most common. This hardness range offers an excellent balance of flexibility, wear resistance, and load-bearing strength, making HNBR seals ideal for both dynamic and static sealing applications in demanding environments.

Color

HNBR O-rings are most commonly green, especially in automotive and refrigeration applications. This color is widely used by many manufacturers to clearly differentiate HNBR from standard black NBR, making it easier to identify in the field.

Benefits of HNBR O-Rings

HNBR O-rings are highly valued for their excellent balance of mechanical strength, flexibility, and chemical resistance. Their unique hydrogenated nitrile composition provides superior durability and abrasion resistance, along with enhanced resistance to heat, oils, and chemicals. These qualities make HNBR O-rings a reliable choice for demanding sealing applications across industries such as automotive, oil and gas, industrial machinery, and hydraulics. Known for maintaining flexibility and sealing integrity under pressure and mechanical stress, HNBR O-rings deliver consistent, long-lasting, leak-free performance even in challenging environments. They offer several key mechanical and chemical advantages, including:

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

Additionally, HNBR O-rings are resistant to:

  • Abrasions
  • Brake fluids
  • Diluted alkalis
  • Grease
  • Mold (some resistance)
  • Oxidation
  • Silicone oils
  • Sunlight
  • Water
  • Weather

Common Uses and Applications of HNBR O-rings

HNBR O-rings are widely used in industries where reliable sealing under tough conditions is critical. They are commonly utilized in automotive fuel systems, air conditioning and refrigeration, oil and gas equipment, hydraulic systems, and industrial machinery. Their excellent resistance to heat, oils, and chemicals makes them ideal for sealing pumps, valves, compressors, cylinders, and other components exposed to harsh fluids and high pressures. Whether in dynamic or static sealing roles, HNBR O-rings deliver dependable performance across a broad range of demanding applications.

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.