Rubber fails at temperature extremes two ways: heat hardens and cracks it; cold stiffens it until it stops sealing and flexing. This chart shows the continuous operating range of each compound we stock — pick the one whose bar covers your application.
Continuous Operating Ranges
| Compound | Low | High | Range visual |
|---|---|---|---|
| Silicone | -70°F | +400°F | |
| EPDM | -40°F | +250°F | |
| Neoprene | -40°F | +200°F | |
| Buna-N (Nitrile) | -30°F | +212°F |
What This Means in Practice
Engine bays, ovens, steam lines: silicone only — everything else hardens within months above 250°F. Outdoor year-round (vehicles, rooftops, boats): EPDM or neoprene both handle -40°F winters; EPDM wins on summer sun exposure. Freezers and cold chambers: silicone stays flexible where others turn brittle. Normal indoor/outdoor service: all four work — choose by chemical exposure instead, using the rubber compatibility chart or the material quiz.
Note: ranges are for continuous service; brief spikes above the limit age rubber faster but rarely cause instant failure. When an application sits near a compound's limit, step up to the next compound.