Leading High-Quality Rubber O-Rings Manufacturer & Supplier in China.
Savvy, as a leading o-ring maker in China, has more than thousands of molds in our factory and can meet your different sizes and shapes of o-ring seal order needs. Our company stocks many imperial and metric o-rings and can arrange delivery instantly by door-to-door courier. Our shipping partner grants us the most favourable discount, so you can only afford the lowest express cost.
O-Ring Products
Except for the traditional standard o-rings, we also manufacture encapsulated o-rings, backup-rings, x-rings, etc. At the same time, since we are a factory, we can make a custom o-ring at a very low mold/tooling cost and fulfill a fast delivery for our customers.
O-Ring Overview
O-Ring is a kind of rubber sealing ring with a circular cross-section to seal various fluids such as air, water, and oil. Because its cross-section is o-shaped, it is called an o-shaped rubber seal, also called an o-ring. It is the most widely used element in hydraulic and pneumatic transmission systems. It is mainly used for mechanical parts to prevent the leakage of liquid and gaseous media under static conditions. In some cases, o-ring can also be used as axial dynamic sealing of reciprocating motion and low-speed rotating motion.
For different types of fixed sealing or dynamic sealing applications, o-ring seals provide designers with an effective and economical sealing element. As a two-way sealing element, the o-ring is installed in the medium groove, and the initial compression in the radial or axial direction during installation gives the o-ring its initial sealing ability. The sealing force produced by the system pressure and the initial sealing force are combined into the total sealing force, which increases with the increase of the system pressure.
O-Ring Materials
O-rings can be made of rubber, metal, and other materials, but rubber is the most used material for o-rings. Savvy can produce popular rubber compounds, as well as some special compounds. According to different working conditions, different materials need to be selected carefully to achieve the best sealing purpose. The most commonly used o-ring materials are NBR, FKM, and Silicone.
NBR is the first considering material we suggest. About 50% of o-rings worldwide are made from NBR compounds due to the compound’s good performance and low cost. Strong oil resistance is one of the biggest advantages of NBR o-rings.
FKM / Viton is an o-ring material with the best comprehensive performance and is widely used in various sealing equipment with high standards. It was first invented by DuPont company and issued under the trade name “Viton”. With the time being, more and more people used to call this material Viton.
Silicone is more and more used in medical and food industries, especially FDA silicone. It is tasteless and non-toxic, not afraid of high temperatures, and resistant to severe cold.
Excepting the above popular rubber materials, other materials like EPDM, HNBR, FFKM, CR, Aflas, etc. are also used in different equipment.
We manufacture the following main rubber material O-Rings with high quality and low price.
O-Ring Properties Table
Different elastomers have different compatibility with various chemical elements, as well as their characteristics. See the table below for more material knowledge so you can order the most cost-effective o-rings from us.
Click image to open expanded view
O-Ring Sizes
An o-ring has three sizes, ID (inside diameter), OD (outside diameter) and CS / W (cross-section / width). Normally to specify the ID and CS is enough, namely, a standard o-ring size will be given, ID 20 x CS 2 mm. From the right picture, you can easily know the
Outside Diameter = Inside Diameter + Cross Section * 2
OD = ID + CS*2
In history, different countries form their own standard o-ring sizes, like AS568 for the USA, BS1516 for the UK, DIN 3771 for Germany, JIS B 2401 for Japan, ISO 3601 for International, and GB 3452.1 for China.
| Country | Standard | Cross Section (mm) | ||||
|---|---|---|---|---|---|---|
| USA | AS568 | 1.78 | 2.62 | 3.53 | 5.33 | 6.99 |
| UK | BS1516 | |||||
| Universal | ISO 3601 | 1.8 | 2.65 | 3.53 | 5.3 | 7 |
| Germany | DIN 3771 | |||||
| France | NFT47 501 | |||||
| Sweden | SMS l586 | 1.6 | 2.4 | 3 | 5.7 | 8.4 |
| Japan | JIS B 2401 | 1.9 | 2 | 2.4 | 3.1 | 3.5 |
| 4 | 5.7 | 6 | 8.4 | 10 | ||
| Others | Preferred Metric Sizes | 1 | 1.5 | 2 | 2.5 | 3 |
| 3.5 | 4 | 4.5 | 5 | 5.5 | ||
| 6 | 7 | 8 | 10 | 12 | ||
O-Ring Hardness
The hardness unit of the o-ring is Shore A, which can be easily measured by a Shore A scale durometer. Generally, the hardness of o-rings is Shore A 50～90, but in use, Shore A 70 is generally more suitable, except for silicone rubber, whose Shore A 60 is generally used. The choice of o-ring hardness is more important. If the hardness is low, it is easy to install but prone to peeling, installation damage, extrusion, and even pressure explosion. If the hardness is too high, the installation is inconvenient. Generally, 50~60 is low hardness, 70~80 is medium hardness, and 88 (or 90) is high hardness. When the sealing pressure is in the range of 30~60 MPa, the hardness of the o-ring seal should be 85~90. In some special cases, the silicone o-ring can be lower at Shore A 25.
| Material | NBR | HNBR | FKM | FFKM | AFLAS | Silicone | FVMQ | EPDM | Neoprene | PU | PTFE |
| Hardness (Shore A) | 70 | 70 | 75 | 75 | 75 | 60-70 | 70 | 70 | 70 | 70-90 | 50 (Shore D) |
| Color | Black | Green | Brown | Black | Black | Red | Blue | Black | Black | Yellow | White |
O-Ring Colors
Savvy can produce o-rings in various colors for customers, and customers need to provide the standard RAL or Pantone color number. However, considering cost and easy identification, it is generally recommended to choose several commonly used colors, such as Black for NBR, Green for HNBR, Brown for Viton, Red / Translucent / White for Silicone, Blue for FVMQ, Yellow for PU, and so on. If you order a unique color that is not commonly used, it may increase the cost and require a larger MOQ with a longer delivery time.
If you need a custom color but don’t know the color number, you can refer to the RAL color chart website at https://www.ralcolorchart.com.
O-Ring Advantages & Disadvantages
O-rings are widely used in various dynamic and static sealing occasions because of their low manufacturing cost and convenient use.
Its advantages include: O-rings are widely valued for their simplicity, versatility, and reliability as sealing solutions. Their primary advantage lies in their ability to create effective static and dynamic seals by deforming under compression to fill gaps, preventing fluid or gas leakage. They are cost-effective due to their simple design and ease of mass production. O-rings are compatible with a broad range of temperatures (-60°C to 250°C, depending on material) and pressures, making them suitable for diverse applications, from hydraulic systems to aerospace engineering. Their compact size allows installation in confined spaces without complex machinery. Additionally, they are resistant to many chemicals, oils, and solvents when made from appropriate elastomers like nitrile, silicone, or Viton®. O-rings also require minimal maintenance and exhibit long service life under proper conditions. Their adaptability across industries—automotive, medical, and industrial—underscores their universal utility.
Its disadvantages include: Despite their benefits, O-rings have limitations. Prolonged compression can cause permanent deformation (compression set), reducing sealing effectiveness over time. Extreme temperatures may degrade performance: high heat accelerates material hardening or cracking, while low temperatures reduce elasticity. Dynamic applications (e.g., rotating shafts) increase friction and wear, shortening lifespan. Improper installation—twisting, overstretching, or incorrect groove sizing—often leads to premature failure. Material incompatibility with specific chemicals can cause swelling, shrinkage, or disintegration. Environmental factors like UV exposure or ozone may also degrade certain elastomers. In critical systems, sudden O-ring failure without warning poses safety risks. Maintenance challenges arise when seals are embedded in complex machinery, requiring disassembly for inspection. Lastly, precise manufacturing tolerances for grooves and surfaces are essential, adding design complexity.