O-Ring & Back-up Rings


Sealparts: Integrated into the global o-ring supply network. We can supply o-rings in more than 2000 sizes in standard and none standard materials from our network stock

 International size standards 

Standard Description  Cross sections
BS 1806 British Inch 1.02 1.27 1.53 1.78 2.62 3.53 5.33 6.99
AS568 American Standard 1.02 1.27 1.53 1.78 2.62 3.53 5.33 6.99
BS 4518 British Metric 1.60 2.40 3.00 5.70 8.40      
SMS 1586 Swedish Metric 1.60 2.40 3.00 5.70 8.40      
DIN 3777-1  German Metric 1.80 2.65 3.55 5.30 7.00      
ISO 3601-1 ISO Standard 1.80 2.65 3.55 5.30 7.00      
JIS B2401 Japanese JIS 1.90 2.40 3.10 3.50 5.70 8.40    
NFT47-501 French Metric 1.80 2.65 3.55 5.30 7.00      


Standard Base Material Compounds                             

Designation   Notes
NBR Acrylonitrile-buta-diene natural rubber
NBR rubber is generally resistant to oils, especially hydraulic oils, lubricants, petrol and other aliphatic hydrocarbons and diluted acids. Good physical characteristics such and good temperature resistance (-25 °C up to +120 °C, in part to -40 °C) give this natural rubber a wide range of uses. 
FKM Fluoro natural rubber Outstanding resistance to mineral oils, aliphatic and aromatic hydrocarbons, as well as CHCs, concentrated and diluted acids, and weak alkalis. Excellent resistance to high temperatures up to 200 °C and a low temperature resistance down to -40 °C. Good mechanical characterstics and an exceptionally good ageing resistance make FKM. Available in generic FKM & genuine Viton.
EPDM Ethylene propylene diene natural rubber EPDM is often design in hot water and steam applications. EPDM is also very resistant to ageing and ozone. Compared with the usual types of synthesis natural rubber it has good resistance to cold temperatures. EPDM is not resistant to aliphatic or aromatic hydrocarbons or mineral oil products. Resistance to chemicals, and also to oxidising agents, is very good. Temperature range from -50 °C to +140 °C depending on type.
AU Polyurethane natural rubber Polyurethane orings generally exhibit very good abrasion resistance and compression set characteristics. Other characterIstics include good gas properties, resistance to fuel, and to many other common technical oils, especially those with higher aromatics content. With a temperature range of -30 °C
 +125 °C and outstanding resistance to oxygen and ozone polyurethane orings work well in many tough applications
PTFE Polytetrafluoro-ethylene
Polytetrafluoro-ethylene have a wide raging resistance to chemicals, exceptionally low friction qualities and good abrasion resistance. Temperature range from -200 °C to +260°C. PTFE has hardness of approximately 95 ° Shore so special attention needs to be taken for housing design and assembly methods
FFKM Perfluoroelastomers
FFKM materials offer the ultimate thermo-chemical resistance shown by the good long-term high temperature compression-set resistance. 

Common Perfluoroelastomers FFKM Types

Peroxide 240°C 
Broad Chemical Resistance

Triazinic 327°C 
High temperature, excellent mechanical properties. Reduced chemical and steam resistance.

Modified Triazinic 275°C 
Broad chemical resistance, excellent mechanical properties.

Modified Peroxide 325°C 
High temperature resistance, excellent mechanical properties, reduced amine and base resistance.

Available in generic FFKM & genuine Kalrez





  • o-rings
    Sealparts: Integrated in the global o-ring supply network. Learn More
  • back-up rings
    Prevent o-ring extrusion using Sealparts back-up rings. Back-up Rings can be used statically or dynamically, over a broad temperature and pressure range. Learn More