HNBR O-Rings (Hydrogenated Nitrile)
Hydrogenated nitrile for high temperatures, ozone resistance, and sour gas service
Overview
HNBR (Hydrogenated Nitrile Butadiene Rubber) is the premium upgrade to standard NBR. By hydrogenating the nitrile polymer, HNBR gains significantly improved temperature resistance, ozone and weathering resistance, and mechanical strength while retaining excellent oil and fuel compatibility.
HNBR is the material of choice for oil & gas downhole seals (NACE MR0175 compliant grades), automotive air conditioning and fuel injection systems, and high-pressure hydraulic cylinders where NBR would fail due to heat or ozone exposure.
Material Properties
| Full Name | Hydrogenated Nitrile Butadiene Rubber |
| Temperature Range | -40°C to +150°C |
| Hardness Range | 50–90 Shore A |
| Color | Black or Green (custom colors available) |
| Elongation at Break | 150–400% |
| Tensile Strength | 15–25 MPa |
| Compression Set (22h / 150°C) | 15–25% |
| Price Index | Moderate-High (3× NBR base) |
| Common Standards | ASTM D2000 DH, SAE AMS3216, NACE MR0175 / ISO 15156 |
Typical Applications
Oil & Gas
Downhole packers, BOP seals, and wellhead seals in sour gas (H₂S) environments.
Automotive
Fuel injection systems, air conditioning seals, and power steering where ozone and heat are present.
Hydraulics
High-pressure cylinder seals and pump shaft seals in mobile and industrial hydraulics.
Aerospace
Fuel system seals and actuator seals requiring improved thermal stability over NBR.
Chemical Compatibility Summary
Compatible With
- - Mineral oils
- - Hydraulic fluids
- - Gasoline and diesel fuels
- - Aliphatic hydrocarbons
- - Silicone oils and greases
Incompatible With
- - Polar solvents (ketones, esters)
- - Aromatic hydrocarbons
- - Chlorinated hydrocarbons
- - Steam and hot water
- - Strong acids
Compare Nearby Materials
Further Reading
HNBR vs NBR O-Rings
Mechanical strength, heat capability, and the real upgrade path over standard nitrile.
Read articleKey Advantages
High Temperature Performance
HNBR extends the useful temperature range of nitrile from +120°C up to +150°C, making it ideal for under-hood automotive and hot hydraulic oil applications.
Ozone & Weather Resistance
Unlike standard NBR, HNBR resists ozone cracking and UV degradation, enabling long-term outdoor and marine service without protective coatings.
Sour Gas Compliance
NACE MR0175 / ISO 15156 compliant HNBR grades are proven in oil & gas environments containing hydrogen sulfide (H₂S).
Mechanical Robustness
Higher tensile strength, tear resistance, and abrasion resistance than NBR, supporting dynamic reciprocating and rotary seals.
Frequently Asked Questions - HNBR
What is the difference between HNBR and NBR?
HNBR is produced by hydrogenating NBR, which removes the double bonds in the polymer chain. This improves temperature resistance from +120°C to +150°C, adds ozone and weather resistance, and increases mechanical strength while maintaining oil and fuel compatibility.
Is HNBR NACE MR0175 compliant?
Yes. We supply HNBR compounds specifically formulated and tested to meet NACE MR0175 / ISO 15156 for sour gas (H₂S) service in oil & gas applications. Certificates are available on request.
When should I choose HNBR over FKM?
Choose HNBR when you need oil/fuel resistance plus mechanical robustness at temperatures up to +150°C. FKM is required for continuous service above +150°C or in highly aromatic fuels. HNBR is typically more cost-effective than FKM for moderate high-temperature oil sealing.
Can HNBR be used with steam or hot water?
HNBR is not recommended for steam or hot water service. For these applications, EPDM is the preferred elastomer due to its superior hydrolysis resistance.
What hardness grades are available for HNBR O-rings?
We stock and manufacture HNBR O-rings from 50 to 90 Shore A. 70 and 80 Shore A are the most common grades for hydraulic and automotive applications.