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O-rings
We can supply you with high-quality O-rings whenever you need them.
KODA offers a full range of O-rings in the following materials: View our size chart for a complete list of all sizes and specifications.
KODA specializes in manufacturing O-rings, rubber accessories, and various seals (including square rings, X-rings, support rings, etc.), consistently providing high-quality products at competitive prices to every customer. Our experienced technical sales team has deep expertise in the sealing industry, possessing a thorough understanding of O-ring performance and application scenarios. We can provide targeted professional selection guidance and customize the best solutions for you.
Still struggling to choose the right seal? Let us help you find the perfect match! For more product information or to get an O-ring quote, please call +8618730921709 or submit a product inquiry form directly.
What are O-rings?
An O-ring is a circular sealing element with a circular cross-section and is one of the most widely used basic seals in the industrial field. Made primarily of rubber, it relies on its own elastic deformation to create contact pressure within the sealing groove, thereby blocking the leakage path of the medium. O-rings are simple in structure, easy to install, and inexpensive. They are suitable for both static and low-speed dynamic sealing applications and can effectively seal various media such as gases and liquids. They are widely used in pipelines, valves, cylinders, and other components in industries such as automotive, hydraulics, pneumatics, construction machinery, and home appliances.
Check O-ring model
The choice of material for O-rings directly determines their sealing performance and adaptability to various operating conditions. The mainstream material is rubber, encompassing multiple categories such as nitrile rubber (NBR), fluororubber (FKM), silicone rubber (VMQ), and ethylene propylene diene monomer (EPDM). Nitrile rubber offers high cost-effectiveness, oil and wear resistance, making it the first choice for general industrial applications; fluororubber is resistant to high temperatures and strong corrosion, suitable for demanding conditions such as chemical and aerospace applications; silicone rubber is non-toxic, odorless, and resistant to high and low temperatures, widely used in food and medical equipment; EPDM excels in weather resistance and acid and alkali resistance, making it suitable for outdoor pipelines and sanitary ware applications. Different O-ring materials have different strengths in hardness, elasticity, and media compatibility, requiring precise selection based on actual operating conditions.
O-ring hardness
The hardness of O-rings is a key indicator of their sealing performance, typically measured in Shore A scale, with a common range between 40 Shore A (soft) and 90 Shore A (hard). Hardness directly affects the compression deformation and resilience of O-rings: low-hardness O-rings have good elasticity and strong fit, suitable for sealing grooves with rough surfaces or large gaps; high-hardness O-rings have excellent wear resistance and strong extrusion resistance, suitable for harsh working conditions with high pressure, high speed, or mechanical friction. Selection requires a comprehensive assessment of the sealing medium, working pressure, and installation gap to ensure that the O-ring is neither too hard to fill the gap under pressure nor too soft to be extruded by the high-pressure medium.
KODA O-ring Part Numbering System
KODA’s O-ring part numbers are designed to describe their material, hardness, size, and any special functions. For example, the image below shows the part number of an O-ring made of nitrile rubber, with a hardness of 70, a size of 131, and a peroxide vulcanization process. See the table below for more abbreviations for materials and special functions.
| Prefix Symbol | Material |
|---|---|
| Material | Shaft tolerance (recommended) |
| A | AFLAS® |
| N | Nitrile |
| BV | Viton® (Brown) |
| V | Viton® |
| E | EPDM |
| HNBR | HNBR |
| HSN | HNBR (Green) |
| F | Fluorosilicone |
| S | Silicone |
| K | Kalrez® (FFKM) |
| P | PERFREZ (FFKM) |
| TEF | Teflon (PTFE) |
| TES | Teflon Encapsulated Silicone |
| TEV | Teflon Encapsulated Viton® |
| C | Neoprene |
| U | Urethane |
| WN | Nitrile (White) |
| WV | Viton® (White) |
| Suffix Symbol | Special Feature |
|---|---|
| Special Feature | Shaft tolerance (recommended) |
| (Blank) | No Special Features |
| ETP | Extreme Temp |
| FDA | FDA-Grade |
| HG | High-Visibility Green |
| HY | High-Visibility Yellow |
| LT | Low-Temp |
| MD | Metal Detectable |
| PC | Peroxide-Cured |
| RGD | Rapid Gas Decompression |
| YW | Yellow |
O-ring color
The intricacies of O-rings go far beyond their simple, visually apparent shape. In many professional industries, color is a key indicator for identifying O-ring types, with different categories corresponding to specific industry color standards. Click here to view our O-ring colors.
Shelf life of O-rings
KODA O-rings, when kept in a sealed, light-proof, dry environment away from oil and corrosive media, have a shelf life ranging from 3 years to indefinite. For more information on O-ring shelf-life recommendations, please click here.
O-groove design
The cross-sectional dimensions, tolerances, and surface roughness of the O-ring groove must be precisely matched with the O-ring specifications to ensure sealing performance and assembly stability. Please click here to view our O-ring groove design guide.
Metric O-ring
KODA supplies a full range of metric O-rings, covering various materials and sizes. Metric means that all dimensions are measured in millimeters. Learn more about metric O-rings.
Custom O-rings
KODA offers a full range of custom O-ring services, supporting customized sealing solutions in different materials (fluororubber, nitrile rubber, silicone, etc.), specifications, and colors based on customer operating conditions, installation dimensions, and media characteristics. Whether it’s fine-tuning standard metric dimensions or custom fitting of non-standard grooves, we ensure through precise mold development and process control that the sealing performance, temperature and pressure resistance, and service life of our custom O-rings perfectly match the actual application scenario, meeting the personalized sealing needs of various fields such as industrial, hydraulic, and pneumatic systems. Learn more about custom O-rings.