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O-rings for industry: sealing rings made from high-quality elastomers for mechanical engineering, plant engineering and technical applications. Find out more now.
Your partner for O-rings
FLAT AND SPECIAL SEALS FROM THE EXPERTS
Your partner for seals
We manufacture special rings for a wide range of applications and the most diverse purposes. O-rings, back-up rings, slide rings, wipers etc., bushes (e.g. bearing bushes), seals (pot seals, chevron seals etc.), balls, bellows and various other seals (piston seals, rod seals, graphite seals) are produced individually to customer requirements.
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O-rings are essential sealing elements used in many industries to reliably seal liquids and gases. Thanks to their simple, proven design, they offer a reliable sealing solution for numerous applications. Our O-rings are available in various materials and dimensions so that you can select the version to suit the medium, temperature and load.
Product description
O-rings are circular, endless rings with a round cross-section. They are usually made from elastomers or thermoplastics and can be installed with radial or axial sealing. The sealing effect is created by the deformation of the O-ring cross-section in the installation space. Under pressure, the material in the contact area behaves almost like an impenetrable fluid, whereby the media pressure additionally supports the sealing function during operation.
Dimensions and sizes
O-rings are available in a broad size spectrum and can therefore be designed for many installation situations. The inside diameter and cord thickness are particularly relevant for selection.
- Inside diameter (d1): 0.5 mm to 10,000 mm
- Cord thickness (d2): 0.5 mm to 40 mm
When designing, the cord thickness must be considered in relation to the installation space, pressure level and type of movement.
Materials and temperature resistance
Depending on the medium, temperature and mechanical load, different materials are available. The following temperature ranges serve as a guide for typical versions.
- NBR (nitrile rubber): -30 °C to +100 °C
- FPM (fluoro rubber): -20 °C to +200 °C
- EPDM (ethylene propylene diene rubber): -40 °C to +140 °C
- MVQ (silicone rubber): -50 °C to +200 °C
- HNBR (hydrogenated nitrile rubber): -30 °C to +150 °C
- PTFE (polytetrafluoroethylene): -200 °C to +260 °C
NBR is often suitable for media containing mineral oil. FPM is typically used at elevated temperatures and in contact with many chemicals.
Areas of application
O-rings are used across industries. The selection depends on pressure, temperature, medium and type of movement.
Static applications
Sealing of stationary machine and system parts against liquids and gases, for example in hydraulic cylinders, flange connections or pipe unions.
Dynamic applications
Sealing of moving parts, for example on rotating shafts or oscillating screw movements, as occur in pneumatic applications and in the automotive industry.
Special sizes and special materials
In addition to standard dimensions, special sizes and application-specific versions are available. Depending on the requirement, O-rings can be produced butt-bonded or butt-vulcanised in order to increase resistance and service life. Special compounds are also possible on request, for example with FDA requirements or increased temperature and chemical resistance.
Installation recommendations
For a reliable sealing function, a correctly designed and cleanly executed installation space is decisive. Surface defects such as notches or scratches in the sealing area affect the function. The groove dimensions must match the cord thickness and the respective application.
Radial installation
Static seal as a rod seal (sealing inwards) or piston seal (sealing outwards).
Axial installation
Static seal as a flange seal.
Storage and care
O-rings should be stored in accordance with DIN 7716 or ISO 2230 in order to reduce ageing, hardening and deformation. Storage rooms should be cool, dry and free from direct light and ozone sources. A typical storage temperature is between +12 °C and +25 °C.
Ordering and service
At least the inside diameter and cord thickness are required for ordering. The material selection depends on the operating conditions and can be agreed with our contacts. State the required quantity, then available options including tolerance ranges will be displayed.
For orders of stock items placed by 16:30, dispatch takes place on the same working day. Our team is available by telephone or email for technical questions and advice.
Our range
In addition to O-rings, we stock other sealing elements such as X-rings, shaft seals and profile cords. Find out about the entire range and available versions in the shop.
O-rings – what are they?
O-rings are ring-shaped seals with a round cross-section that are used in industrial and technical applications to seal liquids and gases. They consist predominantly of elastic materials such as rubber or plastic and are characterised by a simple design combined with a high sealing effect.
Thanks to their elasticity, O-rings adapt to the installation space and retain their sealing function even under pressure and with changing temperatures. They are available in different materials and dimensions and are suitable for both static and dynamic sealing.
Properties of O-rings
- Materials: NBR, EPDM, FKM (Viton), silicone, PTFE
- Sizes: standard dimensions and custom-specific versions
- Temperature resistance: approx. -40 °C to +200 °C, depending on the material
- Application: universal seals for static and dynamic sealing
Further sealing products
X-rings
Square profile with increased sealing effect and reduced friction, often as an alternative to O-rings in dynamic applications.
K-rings
Combined sealing and back-up rings for dynamic sealing, in particular in hydraulic and pneumatic systems.
Back-up rings
Additional stabilisation of O-rings at high pressures, manufactured from materials such as PTFE or polyamide.
Shaft seals
Seals for sealing rotating shafts against liquids and contamination, available in NBR, FKM or silicone.
End caps
Protective caps for open pipe and container ends, manufactured from elastomer or plastic.
V-rings
Axial seals for rotating shafts with a protective function against dirt and moisture.
Gamma rings
Radial shaft seals with an additional sealing lip for protection against external contamination.
Rotary seals
Seals for rotating components with high pressure and temperature resistance, typically made from PTFE or FKM.
Wipers
Remove dirt and foreign matter from moving parts, for example in hydraulic cylinders.
Rod and piston seals
Seals for piston rods and pistons in hydraulic and pneumatic cylinders to ensure reliable movement sealing.
Guide rings and guide strips
Serve to guide and stabilise pistons and rods, often manufactured from PTFE or fibre-reinforced materials.
Bonded seals
Metal-supported seals for bolted connections, consisting of a rubber-metal combination.
O-ring cords and profile cords
Elastomer cords in various diameters and profiles for the production of O-rings or for special sealing tasks.
Milk pipe union rings
Seals for the food and beverage industry, manufactured from silicone, EPDM or PTFE.
Sealing rings to DIN
Flat and profile seals to DIN 7603 and DIN 3869 for bolted and union connections in hydraulic and pneumatic systems.
SAE flange seals
Seals for SAE flange connections with high pressure and temperature resistance.
Packaging and delivery
All sealing products are packed to be safe in transit. Fast and reliable delivery supports smooth processes in industry and trade.
Manufacture of O-rings
O-rings are manufactured from selected elastomers such as NBR, EPDM, FKM or silicone. Depending on the material and application, processes such as pressing, extrusion or injection moulding are used. The material is then cured in order to achieve the desired mechanical properties.
Finally, the O-rings are inspected to ensure dimensional accuracy and functional reliability.
Purpose of O-rings
- Hydraulics: sealing of cylinders, valves and pumps
- Pneumatics: sealing of compressed air systems
- Automotive industry: use in engines, transmissions and air conditioning systems
- Medical technology: safe sealing in devices and instruments
- Household appliances: sealing in fittings, coffee machines and washing machines
IMPRESSIONS FROM SEALING TECHNOLOGY
O-rings
O-rings
O-rings
Frequently asked questions about O-rings
What are O-rings?
O-rings are ring-shaped sealing rings with a round cross-section. They are made from elastic materials such as rubber or silicone and serve to prevent leakage of liquids or gases in technical connections.
Where are O-rings used?
O-rings are used in hydraulic and pneumatic systems, in mechanical engineering, in the automotive industry, in medical technology and in household appliances to reliably seal components.
Which materials are used for O-rings?
Common materials are NBR, EPDM, FKM (Viton), silicone, neoprene and PTFE. The choice of material depends on the temperature range, medium and chemical resistance.
How do you select the right O-ring?
Selection is based on inside diameter, cord thickness, material, permissible temperature range, pressure load and media compatibility of the application.
How are O-rings installed?
O-rings are placed in the grooves provided for them and then assembled. The installation space should be clean, free from burrs and dimensionally accurate in order to avoid damage.
Can O-rings be reused?
O-rings are usually intended for single use. Reuse is only sensible if they are undamaged and the application is unchanged.
How do you care for O-rings?
O-rings should be checked regularly for wear, cracks or deformation. If necessary, they can be cleaned with mild cleaning agents and protected against aggressive media.
How long do O-rings last?
The service life depends on the material, the operating conditions, the temperature, the pressure and the chemical load. Under suitable conditions, service lives of several years are usual.
What are common causes of O-ring failure?
Typical causes are incorrect dimensioning, unsuitable material, overstretching, high temperatures, chemical attack or incorrect installation.
How are O-rings dimensioned?
O-rings are defined by their inside diameter and the cord thickness. These dimensions must be matched exactly to the groove geometry and the application.
How do you check the tightness of an O-ring?
Tightness is checked by pressure tests, functional tests during operation or by visual inspection for escaping media.
Are O-rings temperature-resistant?
Temperature resistance depends on the material used. Depending on the material, applications from low temperatures to high temperature ranges are possible.
How are damaged O-rings replaced?
Damaged O-rings should be replaced promptly. The replacement O-ring must match the respective application in terms of dimensions and material and be installed in accordance with the installation recommendations.
Advantages you can expect from Martan Gummi
Large selection of rubber mats, rubber sheets, O-rings
Individual solutions on site
Rubber processing and sealing technology
Designing, drafting and drawing your parts
The highest degree of precision
XXL machine park, plotting, punching, bonding
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Our industries
Mechanical & plant engineering
Conveyor technology
Food industry
Automotive industry
Packaging industry
Medical / laboratory technology
Vehicle technology
Water technology
Aerospace industry
Rail technology
Shopfitting
Aviation industry
Mechanical & plant engineering
Conveyor technology
Food industry
Automotive industry
Packaging industry
Medical / laboratory technology
Vehicle technology
Water technology
Aerospace industry
Rail technology
Shopfitting
Aviation industry
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