When it comes to choosing rubber materials for high-temperature environments, silicone rubber and fluororubber (FKM) are often the top contenders. Both are widely used in industries such as automotive, aerospace, electronics, and industrial sealing. But when extreme heat resistance is the main requirement, which material performs better?
🔥 Heat Resistance Comparison
Silicone Rubber:
Silicone maintains flexibility and performance in a wide temperature range from approximately -60°C to +230°C, with some high-grade types even enduring up to 250°C or slightly more. It is ideal for static seals, gaskets, and parts in electronics or ovens.
Fluororubber (FKM):
FKM is known for exceptional heat and chemical resistance, typically rated from -20°C to +250°C, and high-end grades like Viton® can go as high as 300°C for short periods. It’s especially suitable for dynamic sealing under harsh conditions such as engines, fuel systems, and oil seals.
✅ Verdict:If your application involves stable, continuous high temperatures, FKM is generally more resistant than silicone. But for long-term use below 230°C and excellent flexibility, silicone is ideal.
🛡️ Other Considerations Beyond Heat
| Property | Silicone | FKM |
| Cold Resistance | ★★★★★ | ★★☆☆☆ |
| Oil Resistance | ★★☆☆☆ | ★★★★★ |
| Chemical Resistance | ★★★☆☆ | ★★★★★ |
| Elasticity | ★★★★★ | ★★★★☆ |
| Price | Low | High |
These comparisons show that silicone is better suited for flexible sealing in low or medium chemical exposure, while FKM is ideal for harsh environments with oil, chemicals, and sustained heat.
💡 Application Recommendations
✅ Choose Silicone Rubber if your application involves:
Food-grade or medical-grade sealing
Oven or electronic component sealing
Low-temperature flexibility requirement
✅ Choose FKM Rubber if your application involves:
Automotive fuel/oil systems
Chemical plant equipment
High-temperature + chemical exposure
📈 Conclusion: Choose According to Real Application Conditions
Both silicone and FKM have strong high-temperature resistance, but they serve different sealing priorities. Instead of asking which one is absolutely better, ask which one suits your actual needs—whether it’s chemical resistance, flexibility, or long-term heat exposure.
📬 Contact OKIN for the Right Rubber Sealing Solution
At OKIN, we provide customized rubber sealing solutions using high-quality silicone, FKM, EPDM, and other rubber materials. Whether you need precision-molded seals or extruded rubber profiles, we can support your industrial sealing needs from start to finish.