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X-Ring Supplier: X-Ring Seals in Standard and Custom Sizes
Quick Answer: CORASEALS supplies X-ring seals in AS568, ISO 3601, metric, and custom dimensions. An X-ring has a four-lobed cross section that creates two sealing contacts per side and improves stability in dynamic grooves. Send the ID, OD, cross section, material, temperature, pressure, medium, and required quantity to receive a quote.
CORASEALS is an industrial seal supplier for buyers who need X-rings, O-rings, backup rings, and custom rubber sealing parts. This X-ring supplier page explains the seal profile, standard dimensions, common materials, and the data required for a quotation.
X-rings are also called quad rings in some markets. Buyers look for an X-ring supplier when a standard O-ring twists in dynamic service or when friction is too high.
X-Ring Profile and Application
An X-ring seal has a four-lobed cross section. The profile creates two sealing contacts on the top side and two sealing contacts on the bottom side. The recessed areas between the lobes hold lubricant and reduce contact width compared with a standard O-ring. This design lowers friction, improves stability, and reduces the risk of spiral twisting in dynamic applications.
X-rings are used in hydraulic valves, pneumatic cylinders, rotary unions, pumps, and face seal grooves. The seal can often be installed in a groove designed for an O-ring with the same cross section and inner diameter. The groove dimensions, squeeze, and clearance still need to be checked because the four-lobed profile has a different contact pattern.
Standard Sizes and Groove Fit
Common standard X-ring sizes follow AS568 sizes from 001 to 475. Common AS568 cross sections include 1.78 mm, 2.62 mm, 3.53 mm, 5.33 mm, and 6.99 mm. Metric sizes follow ISO 3601 cross sections such as 1.8 mm, 2.65 mm, 3.55 mm, 5.3 mm, and 7.0 mm. Standard size availability depends on material and hardness, so confirm the exact size before ordering.
For replacement parts, measure the inside diameter, outside diameter, and cross section. Do not rely only on a model code from a hydraulic cylinder or valve manual. The same code may be used for different profiles in different catalogs.
X-Ring Materials and Temperature Limits
Material selection starts with the fluid and the maximum temperature. The table below lists common X-ring materials and typical properties. The final temperature range depends on the specific compound and service conditions.
| Material | Common Hardness Shore A | Typical Temperature Range | Common Media Notes |
|---|---|---|---|
| NBR | 70, 90 | -30°C to 100°C | Mineral oil, water glycol, fuel oils |
| FKM | 75, 90 | -20°C to 200°C | Mineral oil, fuels, acids, many chemicals |
| EPDM | 70, 90 | -45°C to 150°C | Hot water, steam, some brake fluids; not for most mineral oils |
| Silicone VMQ | 60, 70 | -60°C to 200°C | Dry heat, cold static sealing; not for abrasive dynamic service |
| HNBR | 70, 90 | -30°C to 150°C | Oil, fuel, refrigerant, ozone |
| FFKM | 70, 90 | -15°C to 260°C depending grade | Aggressive chemicals, high temperature, low outgassing |
These values are typical. For critical service, request the material datasheet from the compound supplier and confirm the temperature, pressure, and chemical compatibility for the specific medium.
Hardness, Pressure, and Backup Rings
Common X-ring hardness values are 70 Shore A and 90 Shore A. Harder compounds resist extrusion but require more installation force. For high pressure applications, check the extrusion gap between the shaft and bore. If the gap