Photo: Header HNBR Fastener Seals molded in Mexico with orange rubber

Hydrogenated Nitrile Butadiene Rubber (HNBR) is a high-performance elastomer commonly used for automotive gaskets and seals exposed to heat, oil, fuel, and demanding mechanical environments.

HNBR begins with nitrile rubber (NBR), which is hydrogenated to improve its resistance to heat, oxidation, ozone, and long-term degradation. The result is a durable sealing material that retains the strong oil and fuel resistance of nitrile while providing improved temperature capability and mechanical performance.

For certain applications, HNBR can also provide a cost-effective alternative to higher-cost elastomers such as FKM.

Why Use HNBR for Gaskets and Seals?

HNBR offers a strong combination of temperature resistance, fluid compatibility, and mechanical durability. Depending on the compound and application, HNBR can perform at temperatures around -40°C to +150°C, with specialized formulations capable of operating beyond this range.

Key advantages include:

Excellent oil and fuel resistance – Well suited for contact with petroleum-based oils, fuels, greases, and many automotive fluids.
High heat resistance – Performs at substantially higher temperatures than standard NBR, making it useful for demanding under-the-hood environments.
Strong mechanical properties – High tensile strength and resistance to abrasion and tearing help HNBR withstand demanding applications and repeated mechanical stress.
Good compression-set resistance – Helps seals maintain sealing force after extended periods of compression and temperature cycling.
Improved ozone and oxidation resistance – Hydrogenation significantly improves the aging characteristics of conventional nitrile rubber.

HNBR vs. FKM

HNBR and FKM are both commonly considered for demanding automotive sealing applications, but the best material depends on the specific operating environment.

FKM generally provides superior high-temperature capability and chemical resistance, including better performance in applications where fuel permeation and VOC emissions are critical. HNBR, however, can provide an attractive balance of performance and cost when the application does not require the full capabilities of FKM.

Our engineers evaluate factors including temperature, fluid exposure, pressure, compression, durability requirements, and OEM specifications when recommending an elastomer for a new sealing application.

HNBR Seals Made in Mexico

Check out the gallery below for examples of HNBR components we manufacture for automotive applications at our plant in Tijauna, Mexico.

Have an HNBR gasket or seal you need quoted? Click the “get a quote” button after the gallery.