NBR

In brief

NBR (nitrile rubber) is a synthetic rubber with high resistance to oils, fuels and many hydrocarbons.

Typical fields of use are seals, sheet material and components in the environment of lubricants, hydraulics and fuels.

What NBR is used for in practice

NBR is often chosen when there is media contact with oil or fuel and at the same time a robust mechanical base is required.

For material-based applications such as sheet material, the NBR rubber sheet is a common choice, while for sealing functions an NBR seal is typical.

Classification in comparison with other elastomers

NBR covers the "oil- and fuel-resistant" area very reliably, while other elastomers may have advantages in weather, ozone or temperature depending on the environment.

For a quick material decision in the sealing environment, the overview EPDM vs. NBR vs. silicone helps.

Fundamentals and properties of NBR

Chemical basis

NBR is a copolymer of acrylonitrile and butadiene. The acrylonitrile content largely determines the oil and fuel resistance as well as the mechanical properties.

A higher acrylonitrile content increases the media resistance, but reduces the cold flexibility.

Temperature and media resistance

NBR is typically used in the temperature range of about −30 °C to +100 °C. Higher temperatures are possible for short periods, depending on the compound and duration of use.

There is very good resistance to mineral oils, hydraulic oils, diesel, petrol and greases.

Mechanical properties

NBR offers a balanced combination of abrasion resistance, tensile strength and elasticity. As a result, the material is suitable for dynamic and static applications.

Typical hardness ranges are between 50 and 90 Shore A, depending on the respective compound.

Distinction from other elastomers

NBR is the preferred choice for oil and fuel contact. For applications focusing on weather or ozone resistance, other elastomers are used.

A classification in the material comparison can be found in the overview of EPDM as an alternative elastomer.

Fields of use and typical applications of NBR

Industry and mechanical engineering

NBR is used in mechanical and plant engineering wherever components are permanently in contact with oils, lubricants or fuels.

Typical applications are flat gaskets, moulded parts, damping elements and protective layers in hydraulic or mechanical assemblies.

Vehicle technology and drive systems

In vehicle technology, NBR is used for seals and elastic components in the environment of the engine, transmission and fuel systems.

The combination of media resistance and mechanical load capacity makes NBR suitable for dynamic applications.

General industrial applications

Even outside classic vehicle or machine applications, NBR is used, for example as a rubber sheet, strip material or cut piece for technical purposes.

For flat applications with defined dimensions, NBR rubber sheets are often used.

Typical selection criteria

NBR is chosen when oil or fuel contact is the main focus and at the same time a stable mechanical base is required.

For applications with other environmental requirements, a material-related classification within the elastomer overview is recommended.

Advantages and limits of NBR

Technical advantages

NBR offers very high resistance to mineral oils, hydraulic oils, fuels and greases.

The mechanical properties enable use in static and dynamic applications with permanent load.

Through different compounds, hardness, abrasion resistance and elasticity can be specifically adjusted.

Typical limits

NBR shows limited resistance to weather influences, ozone and UV radiation.

For applications with permanent outdoor weathering or elevated temperatures, other elastomers are more suitable.

Distinction according to operating conditions

In the case of media contact with oil or fuel, NBR remains a proven choice.

For weather-exposed applications, an alternative such as EPDM rubber is available.

Processing, cut to size and delivery forms of NBR

Common delivery forms

NBR is available in different delivery forms, depending on the application and processing goal.

Rubber sheets, roll material, strips as well as prefabricated moulded and sealing parts are common.

Sheet material and cut pieces

NBR rubber sheets are often used as the starting material for technical cut pieces.

The cut to size is carried out mechanically or by waterjet depending on the requirement, in order to achieve clean edges and reproducible dimensions.

For standardised dimensions and individual cut pieces, NBR rubber sheets are available in various thicknesses.

Moulded parts and seals

For series applications, moulded NBR parts are used, such as O-rings, flat gaskets or special profiles.

The respective compound is adapted to the medium, temperature and mechanical load.

Notes on processing

When processing NBR, the service temperature, the media contact and the desired service life must be taken into account.

These factors determine the suitable compound and the appropriate delivery form.

Comparison and material selection

NBR in direct material comparison

NBR is preferably used when components are permanently in contact with oils, fuels or greases.

In these applications, NBR offers a reliable combination of media resistance and mechanical stability.

Distinction from EPDM

EPDM is particularly suitable for applications with weather, ozone or UV exposure.

In the absence of oil or fuel contact, EPDM is often the better choice.

Distinction from other elastomers

Silicone is used at high or very low temperatures, but offers lower mechanical load capacity.

FKM is used at high temperatures and with aggressive media, but is more cost-intensive.

Typical decision questions

The selection of the suitable elastomer depends on the medium, temperature range and mechanical stress.

A systematic overview is provided by the page Elastomers at a glance.

FAQ on NBR

Is NBR oil-resistant?

NBR has a very high resistance to mineral oils, hydraulic oils, fuels and greases and is therefore suitable for oil-carrying applications.

What temperature range does NBR cover?

The typical range of use of NBR is approximately between −30 °C and +100 °C. The exact range depends on the respective compound and duration of use.

Is NBR suitable for outdoor use?

NBR is primarily suitable for indoor applications or protected areas. For permanent weather or UV exposure, other elastomers are used.

When should NBR be chosen instead of EPDM?

NBR is the suitable choice for oil or fuel contact. When focusing on weather and ozone resistance, EPDM offers advantages.

In which forms is NBR available?

NBR is available as a rubber sheet, roll material, cut piece as well as a moulded and sealing part, depending on the application and processing goal.