High Temperature O-Rings
1587 Products
What Are High-Temperature O-Rings?
High-temperature O-rings are molded from silicone rubber, Durometer 70A, rated from −60°F to +400°F. LILY Bearing stocks this compound in two cross-section shapes — round and square — with the same material and temperature rating across both.
Shop by Cross Section Shape
| Shape | Temperature Range | Color | Best Suited For | Note |
|---|---|---|---|---|
| Round | −60°F to +400°F | Clear | General static and dynamic sealing | Same material and temperature rating as square |
| Square | −60°F to +400°F | Red | Static sealing, cost-sensitive applications | Stronger static seal than round, weaker in dynamic service |
Both shapes use the same silicone compound and carry identical temperature ratings, so the choice between round and square comes down to static vs. dynamic service, not heat or material differences.
Where Are High-Temperature O-Rings Used?
- Ovens, dryers, and heat-treatment equipment
- Exhaust systems and engine components
- Food and medical equipment requiring heat resistance
- Lighting fixtures and electrical enclosures
Frequently Asked Questions
Is silicone suitable for oil or fuel exposure?
No — silicone is built for sustained heat, not chemical or petroleum resistance. If a seal will contact oil, fuel, or aromatic mineral oils, an FKM or NBR compound is a better fit.
Should I choose round or square for a static high-heat seal?
Either works, since both share the same temperature rating. Square offers a slightly stronger static seal, while round is the better choice if there's any chance the joint will see motion.
What's the maximum temperature these O-rings can handle?
Both round and square shapes are rated up to 400°F, with a low end of −60°F. For service above 400°F, a specialty FKM or FFKM compound should be considered instead.
