Most O-ring failures are not manufacturing defects — they are material mismatches. An NBR ring in hot oil, or EPDM in a fuel line, will fail no matter how well it is molded. Choosing the compound comes down to three questions.
Chemical compatibility decides everything. NBR handles petroleum oils and fuels well but swells in polar solvents. EPDM is excellent in water, steam and brake fluid, yet destroyed by mineral oil. FKM covers aggressive chemicals and fuels at a higher price. When in doubt, send us the fluid name — we check compatibility charts before quoting.
| Material | Typical range | Best for |
|---|---|---|
| NBR | -40°C to +120°C | Hydraulics, fuel, general industry |
| FKM (Viton®) | -20°C to +200°C | Engines, chemical processing |
| Silicone (VMQ) | -60°C to +230°C | Food, medical, extreme temperatures |
| EPDM | -50°C to +150°C | Water, steam, outdoor weathering |
| FFKM | -15°C to +320°C | Semiconductor, aggressive chemistry |
Dynamic seals — rods, pistons, rotary shafts — need low friction and high abrasion resistance; polyurethane or filled PTFE often beats rubber here. Static face seals are more forgiving and let you optimize purely for fluid and temperature.
Tell us three things — fluid, temperature range, and whether the seal moves — and we will recommend the compound, hardness and size. That is exactly what our engineering team does with every RFQ, free of charge.
Send us your drawing or operating conditions — our engineers will recommend the right material and size within 24 hours.