Feeling overwhelmed by the options when selecting O-ring materials? Choosing the wrong type can lead to chemical incompatibility, leaks, or premature failure.
EPDM O-rings are best for water, steam, and weather-resistant applications, while FKM (Viton®) O-rings offer superior resistance to oils, fuels, and high temperatures.
Let’s break down the key differences in performance, chemical compatibility, temperature range, and cost between EPDM and FKM to help you make the right decision.
What Is EPDM and What Is FKM?
Wondering what these acronyms even mean? Understanding the base materials is the first step in choosing the right O-ring1.
EPDM (Ethylene Propylene Diene Monomer)2 is a synthetic rubber widely used for its resistance to weather, steam, and polar fluids.
FKM (Fluorocarbon Rubber)3, commonly known by the brand name Viton®, is known for its outstanding resistance to oils, fuels, and high temperatures.
EPDM vs FKM: Performance Comparison Table
Still not sure which is best for your project? A side-by-side comparison makes the choice much clearer.
| Property | EPDM O-Rings ✅ | FKM O-Rings (Viton®) ✅ |
|---|---|---|
| Temperature Range4 | -50°C to +125°C | -20°C to +230°C |
| Weather/Ozone Resistance | Excellent | Excellent |
| Oil/Fuel Resistance5 | Poor | Excellent |
| Water/Steam Resistance | Excellent | Poor |
| Chemical Resistance6 | Good with polar substances (e.g. alcohols, ketones) | Excellent with non-polar substances (e.g. oils, fuels, hydrocarbons) |
| Compression Set Resistance | Good | Excellent |
| Flexibility at Low Temps | Excellent | Limited |
| Cost | Lower | Higher |
When Should You Use EPDM O-Rings?
Is your system handling steam, water, or outdoor exposure? If so, EPDM is often the better choice.
EPDM O-rings perform exceptionally well in outdoor environments, water systems, and applications involving glycol-based fluids or steam.
✅ Best Use Cases for EPDM O-Rings7:
- Plumbing and water systems
- HVAC seals and gaskets
- Brake systems using glycol-based fluids
- Weather and ozone-exposed outdoor equipment
- Steam sealing applications (up to 150°C in some cases)
Avoid EPDM in contact with oils, fuels, and most hydrocarbons.
When Should You Use FKM O-Rings8?
Need a seal for fuel, oil, or high heat? This is where FKM shines.
FKM O-rings are ideal for applications involving aggressive chemicals, oils, fuels, and high temperatures.
✅ Best Use Cases for FKM O-Rings:
- Automotive fuel systems and engine seals
- Aerospace and aviation hydraulic systems
- Chemical processing equipment
- Oil and gas industry
- High-temperature sealing (up to 230°C)
Avoid FKM in applications involving steam, amines, or strong polar solvents like ketones or acetone.
EPDM vs FKM O-Rings: Which Should You Choose?
Feeling stuck between the two? Use the following quick guide to decide:
| Application Condition | Recommended O-Ring Type9 ✅ |
|---|---|
| Water/Steam | EPDM |
| Fuel or Engine Oil | FKM |
| Outdoor/UV Exposure | EPDM |
| High Temperature (>200°C) | FKM |
| Glycol Fluids (Brake) | EPDM |
| Chemical (non-polar solvents) | FKM |
| Budget-Friendly Option | EPDM |
Conclusion
EPDM and FKM O-rings each have unique strengths. EPDM is ideal for water, steam, and weather exposure, while FKM excels in resisting oils, fuels, and heat. Match the O-ring material to your application’s environment to avoid seal failure and ensure long-term performance.
🚀 Need Help Choosing the Right O-Ring Material?
Contact Julong Rubber today or Request a Custom Quote for custom EPDM or FKM O-rings.
Or reach out directly via WhatsApp:
Discover essential factors for selecting the right O-ring to ensure optimal performance in your projects. ↩
Explore the benefits of EPDM to understand its applications and advantages in various industries. ↩
Learn about FKM's unique properties and its applications to see why it's preferred in high-temperature environments. ↩
Understanding the temperature range helps in selecting the right O-Ring for your application, ensuring optimal performance. ↩
Exploring this comparison is crucial for applications involving oils and fuels, ensuring durability and reliability. ↩
Knowing the chemical resistance can prevent failures in critical applications, making this information vital for decision-making. ↩
Discover the best use cases for EPDM O-Rings to ensure you select the right sealing solution for your needs. ↩
Explore this link to understand the diverse applications of FKM O-rings in various industries, enhancing your knowledge on their benefits. ↩
Discover how to select the best O-Ring type for your needs, ensuring optimal performance and longevity in various conditions. ↩
