Custom FKM O-Rings Ø2–300 Mm ID 0.5–10 Mm Cross-Section 70±5 Shore A For High Pressure Industrial Sealing

Product Overview

Our custom FKM O-rings are designed for demanding static and dynamic sealing applications where ordinary rubber materials may not provide sufficient resistance to heat, oils, fuels or aggressive operating environments. Manufactured from fluorocarbon rubber, these O-rings are available with an outside diameter of 3–300 mm, inside diameter of 2–300 mm and cross-section diameter of 0.5–10 mm. The standard hardness is 70±5 Shore A, while other specifications can be evaluated according to the customer’s drawing, sample and working conditions.

FKM O-rings can be used for bore sealing, shaft sealing, water sealing, dust protection and fixed static sealing. They are suitable for pumps, valves, hydraulic equipment, automotive assemblies, chemical-processing equipment and industrial machinery. Custom sizes, colors and compound formulations are available for prototype development and volume production.

Cause

Leakage is a common problem in pumps, valves, hydraulic systems and mechanical assemblies. It may occur because the selected O-ring has the wrong size, unsuitable material, incorrect hardness or insufficient resistance to the operating medium.

Common causes of O-ring failure include:

• Excessive swelling after contact with oil, fuel or chemicals
• Hardening, cracking or loss of elasticity at elevated temperatures
• Insufficient compression inside the sealing groove
• Excessive compression resulting in permanent deformation
• Incorrect cross-section diameter or groove dimensions
• Cutting or twisting during installation
• Abrasion in reciprocating or rotating applications
• Pressure extrusion through the clearance between metal components
• Dust or contamination entering the sealing interface
• Reusing an O-ring that has already experienced compression set

Standard nitrile or silicone rubber may be suitable for many general applications, but they may not provide the required performance in certain high-temperature, fuel-contact or chemical-contact environments. The complete operating conditions must therefore be evaluated before selecting the sealing material.

Solution

FKM, commonly known as fluorocarbon rubber, is widely used for industrial sealing components that require reliable resistance to heat, oils, fuels and many chemicals. Its low gas permeability and good compression-set resistance also make it suitable for long-term static sealing.

We manufacture FKM O-rings according to standard dimensions or customized drawings. The inside diameter, outside diameter, cross-section, hardness and compound can be selected according to the sealing groove and operating conditions.

Our customization process can include:

1. Review of drawings, dimensions or physical samples
2. Evaluation of pressure, temperature and contact medium
3. Material and hardness recommendation
4. Mold development for non-standard sizes
5. Prototype or pre-production sample manufacturing
6. Dimensional and appearance inspection
7. Customer assembly and sealing verification
8. Stable batch production after sample approval

For high-pressure applications, we also evaluate the sealing clearance, groove dimensions and risk of extrusion. A backup ring or structural adjustment may be recommended where pressure, clearance or movement could force the O-ring out of its groove.

Specifications

*Pressure capability depends on groove design, sealing clearance, temperature, working medium, movement, O-ring size and the use of backup rings. Final suitability must be confirmed through application testing.

Application

Hydraulic and Pneumatic Equipment

FKM O-rings can be installed in hydraulic valves, cylinders, connectors and pressure-control components. They form a seal between mating surfaces and help prevent the leakage of oil, gas or other working media.

Pumps and Valves

In pumps and valves, the O-ring can be used around housings, stems, fittings, flanges and internal connections. It is suitable for both fixed sealing points and certain controlled-motion applications.

Automotive Systems

Custom FKM seals are used in automotive fuel systems, engines, transmissions, sensors, connectors and fluid-handling assemblies where resistance to oil, fuel and elevated temperatures may be required.

Chemical-Processing Equipment

FKM O-rings can provide static sealing for pipelines, instruments, filters, dosing equipment and chemical-processing machinery. The specific chemical must be provided before material compatibility is confirmed.

Industrial Machinery

Typical applications include mechanical equipment, compressors, automated production systems, lubrication systems and industrial connectors. The O-ring can provide liquid sealing, dust protection or separation between different media.

Electronic and Electrical Assemblies

FKM O-rings can be fitted into equipment housings, sensors and connectors to reduce the entry of dust, moisture or processing fluids. The sealing performance depends on the enclosure and groove design.

Bore, Shaft and Fixed Sealing

Our FKM O-rings can be customized for:

• Hole and bore sealing
• Shaft sealing
• Water sealing
• Dust sealing
• Fixed static sealing
• Flange and housing sealing
• Connector sealing
• Pump and valve sealing

How It Works

An O-ring works by being installed into a specially designed groove and compressed between two mating surfaces. This initial compression fills the sealing clearance and creates contact pressure around the circumference of the ring.

When fluid or gas pressure increases, the medium pushes the O-ring toward the low-pressure side of the groove. The elastic rubber deforms and increases its contact with the sealing surfaces, helping prevent the medium from passing through the gap.

In a static application, the O-ring remains compressed between components that do not move relative to each other. Typical examples include flanges, housings, plugs and fixed connectors.

In a dynamic application, one surface may reciprocate or rotate. These applications require additional consideration of friction, lubrication, surface finish, speed, temperature and wear. Dynamic suitability should be evaluated according to the complete equipment design rather than pressure alone.

Correct compression is critical. Too little compression may result in leakage, while excessive compression may increase friction, accelerate deformation and shorten service life.

How to Choose

1. Confirm the O-Ring Dimensions

Provide the inside diameter and cross-section diameter whenever possible. If only the outside diameter is known, the other dimensions must be calculated and confirmed carefully.

For a standard round O-ring:

Outside Diameter = Inside Diameter + 2 * Cross-Section Diameter

2. Identify the Working Medium

Specify whether the O-ring will contact:

• Hydraulic oil
• Lubricating oil
• Fuel
• Water
• Gas
• Cleaning agents
• Acids or alkalis
• Solvents
• Other chemicals

“Chemical resistant" does not mean compatible with every chemical. The concentration, temperature and exposure time must also be considered.

3. Provide the Operating Temperature

The appropriate temperature range depends on the selected FKM compound. Please provide the continuous working temperature, maximum temperature and minimum temperature so that the material can be evaluated correctly.

4. Confirm Static or Dynamic Use

Static sealing generally places less wear on the O-ring. Reciprocating or rotating applications require evaluation of speed, lubrication, friction and surface finish.

5. Check Pressure and Clearance

For applications approaching 20 MPa, provide the maximum pressure, pressure direction, groove dimensions and clearance between components. A backup ring may be required to reduce extrusion risk.

6. Select the Correct Hardness

The standard hardness is 70±5 Shore A, offering a balance between elasticity and mechanical support. Other hardness levels may be considered for special groove, pressure or assembly requirements.

7. Send a Drawing or Sample

For faster evaluation and quotation, please provide:

• Inside diameter
• Outside diameter
• Cross-section diameter
• Dimensional tolerance
• Material requirement
• Hardness
• Working temperature
• Working pressure
• Contact medium
• Static or dynamic application
• Estimated order quantity

FAQ

1. What is the difference between FKM and ordinary rubber O-rings?

FKM is a fluorocarbon rubber commonly selected for applications involving heat, oil, fuel and certain chemicals. Ordinary rubber materials may offer different performance or lower cost, so the correct material should be chosen according to the actual working environment.

2. Can you manufacture non-standard FKM O-ring sizes?

Yes. We accept customized inside diameters, outside diameters and cross-sections based on customer drawings or physical samples. Mold development may be required for non-standard specifications.

3. Can these FKM O-rings withstand 20 MPa pressure?

They may be used in systems with pressures up to 20 MPa when the groove, sealing clearance, size, hardness, temperature and operating medium are appropriate. Pressure resistance cannot be determined by material alone. Application testing is required.

4. What information is needed for a quotation?

Please send the O-ring dimensions, required quantity, hardness, color, operating temperature, maximum pressure, contact medium and application type. Drawings or samples are especially helpful for customized products.

5. Do you provide samples before mass production?

Yes. Samples can be produced for dimensional inspection, material evaluation and assembly testing. Mass production can begin after the specification and sample have been approved.

Request a Custom FKM O-Ring Quote

Send us your drawing, required size, working medium, temperature, pressure and estimated purchasing quantity. We provide customized FKM O-ring development for international OEM customers, equipment manufacturers and industrial distributors, covering prototype sampling, non-standard mold development and stable volume production.