Description
O-ring is a ring seal with an O-shaped (circular) cross-section. It is generally installed in grooves, used as a seal for oil, water, air, gas and other fluids, with moderate compression.
d1: Inside Diameter，d2: Width
Used for Static Sealing and Dynamic Sealing, if not follow the conditions of use, it will cause cut off, swelling, compression cracks and other problems.
In order to maintain the long-life sealing, it is necessary to choose the right material and sizes, according to the operation condition.
The sealing principle of O-ring is that the compressed O-ring seals by maintaining the rebound force.
Standards
We provide a variety of metric and inch O-rings with different size standards. Check out our guide to International O-Ring Size Standards.
SAE AS568
DIN ISO 3601
JIS B 2401
Media
| Material
| NBR | HNBR | FKM | EPDM | VMQ |
| Lubricating oil | Engine oil | ֍ | ֍ | O | X | ∆ |
| Gear oil | ֍ | ֍ | O | X | ∆ |
| Machine oil | ֍ | ֍ | ֍ | X | O |
| Cylinder oil | ֍ | ֍ | ֍ | X | ∆ |
| Refrigerating oil (mineral oil) | O | O | ֍ | X | ∆ |
| Cup grease | ֍ | ֍ | ֍ | X | ∆ |
| Lithium grease | ֍ | ֍ | ֍ | X | ֍ |
| Silicone grease | ֍ | ֍ | ֍ | ֍ | X |
| Hydraulic oil | Pulley oil | ֍ | ֍ | O | X | O |
| Oil + water emulsion | ֍ | ֍ | ∆ | ∆ | ∆ |
| Water-glycol type | O | O | ∆ | ֍ | ∆ |
| Phosphate ester | X | X | ֍ | ֍ | O |
| Silicon-based | ֍ | ֍ | ֍ | ֍ | X |
| Brake oil | ∆ | ∆ | ∆ | ֍ | O |
| Hydraulic torque converter oil | ∆ | ∆ | O | X | ∆ |
| Fuel | Light oil • lamp oil | ∆ | O | ֍ | X | X |
| Heavy oil | ∆ | ∆ | ֍ | X | X |
| Gasoline | ∆ | ∆ | ֍ | X | X |
| Water | under 60℃ | O | ֍ | ֍ | ֍ | O |
| under 100℃ | ∆ | O | O | ֍ | O |
| under 150℃ | X | X | X | O | X |
| Coolant | Antifreeze Solution (LLC) | O | O | ∆ | ֍ | ∆ |
| Water-soluble cutting oil | O | O | ∆ | ∆ | ∆ |
| Chemical | Hydrochloric acid 20% | ∆ | ∆ | O | ֍ | ∆ |
| Sulfuric acid 30% | O | O | O | ֍ | O |
| Nitric acid 10% | X | X | ∆ | O | X |
| Caustic soda 30% | ֍ | ֍ | X | ֍ | X |
| Benzene | X | X | ∆ | X | X |
| Trichloro ethylene | X | X | ∆ | X | ∆ |
| Ethyl alcohol | O | O | O | ֍ | O |
| Glycol | ֍ | ֍ | ֍ | ֍ | ֍ |
| Acetone | X | X | X | O | ∆ |
| Gas | LPG | O | O | ֍ | X | X |
| City gas | O | O | ֍ | ∆ | ∆ |
| Ozone (Atmosphere) | ∆ | O | ֍ | ֍ | ֍ |
| Freon R134a | X | ∆ | X | ֍ | X |
| Others | Food※ | ※ | ※ | ※ | ※ | ※ |
| Water※ | ※ | | ※ | ※ | |
| Vacuum ATM~10-4 mmHg | ֍ | ֍ | ֍ | | |
| Vacuum 10-4 ~ 10-9 mmHg | | | ֍ | | |
֍: satisfactory
O: fair
∆: conditional
X: unsatisfactory
※: If the O-rings are used in food, water or related equipment, a special manufacturing process is required, pleaseContact us.
Temperature
| Material | NBR | HNBR | FKM | EPDM | VMQ | PU (AU) |
| Min. (℃) | - 25 | - 30 | - 15 | - 40 | - 45 | - 30 |
| Max.(℃) | + 100 (120) | + 130 (150) | + 200 (220) | + 130 (150) | + 200 (220) | + 80 (100) |
Note: the use of temperature range is affected by sealing medias, use conditions, required performance and other factors.
Max. T: This value accounts the results of air heating degradation testing. The number shown in ( ) is the heat-resistant temperature under temporary use, should be avoided for a long period of continuous use.
Min. T: Suit for TR10。TR is Temperature-Retraction, indicating the recovery of deformation in low temperature. TR10 value refers to the pre-given temperature when deformation recovery 10%, is the standard value of low temperature service limit.
Pressure
| Operation Pressure | Material Hardness |
≤16 MPa
| 70 Shore A
|
>16 MPa
| 90 Shore A
|
| Operation Pressure | Material Hardness |
≤6,3 MPa
| 70 Shore A
|
>6,3 MPa
| 90 Shore A
|
Avoid damaging the O-ring during installation, as this will cause leakage. Observe the following:
The O-ring must not be expanded to its elongation limit.
Edges must be burr-free, radii and angles applied smoothly.
Dust, dirt, metal chips and other particles must be removed.
Tips of screws and installation housings for other sealing and guiding elements should be covered by an assembly sleeve.
A suitable grease to be applied to the assembly surfaces and O-rings.
Elastomer materials are made smoother if they are heated in oil or hot water to approx. 80°C. This makes it easier to stretch the O-ring for assembly.
Any assembly tools used, such as expansion mandrels or sleeves, should be made of a soft material (e.g. POM) and not have any sharp edges.
The O-ring should not be rolled over assembly surfaces. Ensure the O-ring is not twisted as it slots into the groove.
