Material

HNBR (Hydrogenated Nitrile)

Hydrogenating the NBR backbone removes most of the residual unsaturation, substantially improving heat, ozone and abrasion resistance over standard nitrile while retaining strong oil and fuel compatibility — the usual step-up material when NBR runs too hot or wears too quickly.

HNBR O-rings — heat and ozone resistant upgrade from NBR.

Material Data Sheet

Temperature range

-25 °C to +150 °C (+165 °C short-term)

Hardness range

55–90 Shore A

Resists

Oils, fuels, ozone, higher heat than standard NBR, abrasion and tear resistance

Avoid with

Aromatic solvents, brake fluid (glycol-based)

Applications

Where it's used

Automotive timing and drivetrain seals, oilfield elastomer components, compressor seals.

Properties

Key advantages of HNBR

Superior heat resistance over standard NBR — service up to +150°C continuously
Excellent resistance to ozone, weathering and UV ageing
Retains NBR-level oil and fuel resistance at higher temperatures
Very good abrasion and extrusion resistance for dynamic seals
Used extensively in automotive timing-belt covers, AC systems and oil-field downhole seals

HNBR is the preferred upgrade path when an NBR compound has reached its thermal or ozone-resistance limit. FITCO offers HNBR O-rings and seals in standard and custom sizes, with compounds tuned for specific oil-field sour-gas (H₂S) or automotive coolant environments.

Available as