Rubber O-rings

O-rings are among the most widely used seals and are indispensable in virtually every technical sector. Their mode of operation is as simple as it is ingenious: a round sealing ring made of elastic material is inserted into a groove and, through the forces that occur, presses evenly against the surrounding surfaces.

In this way, a reliable seal against liquids, gases or dust is created. Rubber O-rings in particular are of central importance, as they are not only adaptable but also available in a wide variety of qualities and materials.

This versatility makes them an indispensable component both in large-scale industrial production and in everyday applications.

Materials of O-rings

The choice of material is decisive for the performance of an O-ring. Not every rubber is suitable for every application, as temperature ranges, chemical resistance and mechanical stresses vary greatly. Modern elastomers allow precise adaptation to the requirements of the respective sector.

NBR (nitrile rubber)

NBR is regarded as the classic among O-ring materials. It offers excellent resistance to mineral oils, greases and fuels. As a result, it is widely used in hydraulics and pneumatics, but also in the automotive industry.

NBR O-rings are also comparatively inexpensive and cover a large temperature range. They are eminently suitable for applications with moderate loads and are regarded as an economical standard solution.

EPDM (ethylene propylene diene rubber)

EPDM scores with its outstanding resistance to weather, UV radiation and ozone. It is therefore used primarily outdoors and in water-carrying systems.

Typical examples are heating systems, seals in drinking water supply and applications in solar thermal energy. In addition, EPDM O-rings are resistant to many cleaning and disinfecting agents, which makes them particularly interesting for hygienic areas.

FKM (Viton®)

FKM is a high-performance material that is used where temperatures, chemicals or pressures reach extreme values. O-rings made of FKM withstand temperatures up to +200 °C permanently and are resistant to fuels, oils, solvents and numerous aggressive chemicals.

They are frequently used in aviation, engine construction and the chemical industry and are regarded as a premium solution for the most demanding environments.

Silicone (VMQ)

Silicone O-rings are known for their elasticity even under extreme cold conditions. Even at -60 °C they remain flexible and reliable. They are also physiologically harmless and therefore a preferred choice in the food industry, medical technology and pharmaceuticals.

Their disadvantage: silicone is not resistant to oils and fuels, which limits the range of applications. In return, they offer outstanding ageing resistance and are odourless and tasteless.

Other special elastomers

In addition to these standard materials, there are numerous special materials. These include:

• HNBR (hydrogenated NBR): Improved temperature and ozone resistance combined with oil resistance.
• FFKM (perfluoroelastomers): Extremely resistant to virtually all chemicals and temperatures above 300 °C. They are used primarily in highly sensitive chemical processes.
• CR (chloroprene rubber): Robust against weather, cold and moderate chemical exposure.

Areas of application of O-rings

Rubber O-rings can be used universally and play a role in virtually all technical areas. They are used both in static connections, in which the sealing surfaces do not move, and in dynamic applications.

Hydraulics and pneumatics

In hydraulic systems, O-rings prevent the escape of hydraulic fluids at high pressures. They are used in pumps, cylinders, control and regulating valves.

In pneumatic systems, they perform a similar task by reliably sealing compressed air and thus ensuring efficient operation of the systems.

Mechanical engineering and the automotive industry

In mechanical engineering, O-rings are a standard component used in gearboxes, axle bearings, pumps and valves. In the automotive industry, they ensure tightness in air conditioning systems, engines, fuel lines and brake systems.

Modern vehicles often contain several hundred O-rings in a wide variety of sizes and materials.

Chemical industry

The requirements for seals in chemical production are particularly high. Here, O-rings must withstand aggressive media such as acids, alkalis or solvents. FKM and FFKM O-rings guarantee a reliable seal in these environments even under extreme conditions.

As a result, they contribute significantly to the safety of processes and systems.

Food and medical technology

Particularly strict standards and hygiene regulations apply here. O-rings made of silicone or EPDM meet these requirements, as they are odourless and tasteless and in many cases have FDA or EU approvals.

They are used in filling plants, medical devices, pumps and hoses where absolute purity is required.

Construction and everyday life

O-rings also play an important role in construction. They seal water pipes, heating pipes or fittings.

In everyday life, they are found in household appliances such as coffee machines, garden pumps or water filters.

Advantages of rubber O-rings

Rubber O-rings impress with a combination of properties that make them irreplaceable in virtually every sector. They offer a reliable sealing effect, as the elastic material adapts optimally to the surrounding surfaces and thus ensures a secure seal.

At the same time, they are very cost-efficient, as they can be produced cheaply in large quantities and are available in numerous standard sizes. Installation is straightforward, often without special tools, which saves time and facilitates handling. In addition, the variety of materials ensures that the right O-ring can be found for virtually every area of application – from oil and petrol resistance to weather resistance and extreme temperatures.

A further advantage lies in standardisation: standardised sizes allow problem-free replacement and guarantee repeatable quality over long periods of time.

Tips for selection and use

The correct selection of the O-ring is decisive for the service life and function of the entire system. The following points should be observed:

• Temperature range: Must match the material.
• Medium: Oil, water, chemicals or food require special materials.
• Pressure conditions: The higher the pressure, the more important the correct design.
• Movement: Static or dynamic application influences the service life.
• Standard sizes: O-rings are manufactured according to internationally valid DIN and ISO standards.

In summary

Rubber O-rings are small but essential components without which numerous applications would be inconceivable. Their versatility with regard to materials, sizes and possible uses makes them an indispensable part of modern technology.

With the right choice of material, failures can be prevented, maintenance costs reduced and the service life of machines considerably extended. Whether in the automotive industry, in construction, in food production or in highly sensitive chemical processes – rubber O-rings offer the right solution for every challenge.

Frequently asked questions

Which O-ring materials are suitable for high temperatures? FKM and FFKM O-rings are suitable for high temperatures, as they withstand temperatures of over 200 °C and 300 °C respectively.

Which O-rings are approved for contact with drinking water? EPDM O-rings are a proven solution for drinking water applications and generally meet the relevant standards.

Can O-rings be used more than once? In principle, O-rings should be replaced during every maintenance operation or dismantling, as material fatigue or microscopic damage can affect the sealing effect.

How do I find the right size for my O-ring? The dimensions of an O-ring are specified by the inside diameter and the cord thickness. Both can be determined exactly with a vernier calliper.

How long do rubber O-rings last? The service life depends heavily on the material, the load and the ambient conditions. While NBR O-rings last several years in hydraulic applications, FKM or FFKM O-rings can seal reliably for decades with an optimal design.

What happens if the wrong material is chosen? The wrong material can lead to premature failure – for example through swelling, hardening or cracking. The right choice of material is therefore decisive.

Our rubber sheets

For industry and trade, we offer a wide variety of rubber sheets.

SBR rubber sheet

Our high-quality SBR rubber sheet (styrene-butadiene rubber) is the solution for numerous industrial and commercial applications. This rubber sheet is manufactured from first-class styrene-butadiene rubber and is distinguished by its outstanding physical properties.

EPDM rubber sheet

Discover the versatility and reliability of our EPDM rubber sheet, which is manufactured from ethylene propylene diene monomer (EPDM). This high-quality elastomer solution has been specially developed to meet the most demanding industrial and commercial applications.

NBR rubber sheet

The NBR rubber sheet is a high-quality industrial product that has been specially developed for applications requiring excellent resistance to oils, greases and various chemicals.

Viton rubber sheet

The Viton rubber sheet is a high-quality technical product that is used for a wide range of industrial applications. Manufactured from fluoro rubber (FKM), it offers outstanding properties that make it the ideal choice for extreme conditions.

FKM rubber sheet

The FKM rubber sheet is a high-quality technical product that is ideal for use in demanding industrial applications. Made from fluoro rubber (FKM), it is distinguished by a wide range of outstanding properties that make it the optimal choice for extreme operating conditions.

Silicone rubber sheet

The silicone rubber sheet is a first-class technical product that has been specially developed for applications placing high demands on temperature resistance and flexibility.

PUR rubber sheet

The PUR rubber sheet, manufactured from high-quality polyurethane, is a technically advanced product that has been developed for applications placing the highest demands on abrasion resistance and mechanical load capacity.

Neoprene rubber sheet

The neoprene rubber sheet, manufactured from high-quality chloroprene rubber (CR), is a versatile technical product that is ideal for a wide range of industrial and commercial applications.