Mr O-Ring 332 Viton O-Ring 90A Durometer - Pack of 25

Our review of the Mr O-Ring 332 Viton O-Ring finds it best suited for technicians and maintenance pros who need a reliable, high-temperature seal in petroleum, fuel, and chemical environments. The single biggest reason to buy is its material: 90A Viton (FKM) provides proven resistance to fuels, oils, ozone and high heat up to 232C (450F), making this pack of 25 a practical choice when replacing worn seals or stocking a service kit. The review focuses on real-world sealing performance, dimensional accuracy, and suitability across common industrial applications.

Key Features

• Material: Viton FKM offers strong resistance to petroleum products, solvent exposure and many organic chemicals, reducing premature seal failure in aggressive fluids.
• Temperature range: Rated from -26C (-15F) to 232C (450F), the o-ring tolerates a wide range of operating temperatures for hot engines and heated process lines.
• Hardness: The 90A durometer balances firmness and compression set resistance, maintaining a stable seal under pressure and repeated cycling.
• Dimensions: Nominal 2-3/8 in ID, 2-3/4 in OD and 3/16 in CS with actual measurements of 2.350 in ID, 2.770 in OD, 0.210 in CS for predictable fit in AS568-size applications.
• Pack quantity: Supplied as a pack of 25, convenient for field service crews or stocking consumables for routine maintenance.
• Application versatility: Performs well in fuels, diesel blends, oils, silicone lubricants and exposure to ozone or weather, supporting varied sealing needs.

Who It's For

This pack is aimed at mechanics, HVAC and hydraulic technicians, and industrial maintenance teams who repair pumps, valves and fuel system components that encounter fuels, oils and elevated temperatures. The consistent durometer and AS568 sizing make it useful when exacting dimensional control matters for leak-free assemblies.

Those who should look elsewhere include users needing a softer compound for low-pressure water sealing or food-grade elastomers; Viton FKM is not intended where regulatory food contact approvals or very low temperature flexibility below -26C is required.

Pros & Cons

Pros

• Excellent chemical and high-temperature resistance for long-lasting seals in fuel and oil environments.
• Accurate actual dimensions (2.350 in ID, 2.770 in OD, 0.210 in CS) that match AS568 sizing expectations for easy replacement.
• Pack of 25 helps reduce downtime by providing spares for multiple repairs.
• 90A durometer provides a durable, compression-resistant seal suitable for many dynamic and static applications.

Cons

• Viton FKM is not the best choice where very low temperature flexibility or food-grade certification is required.
• Higher durometer can be firmer than desirable in some low-pressure, low-friction sealing applications.

Specifications

Our Verdict

The Mr O-Ring 332 Viton 90A in a pack of 25 is a pragmatic choice for professionals who need a resilient, high-temperature seal that resists fuels and many chemicals. Its accurate dimensions, durable 90A hardness and wide temperature tolerance make it good value for maintenance teams that replace o-rings frequently, though those needing food-grade or very low temperature flexibility should consider alternate compounds.

Frequently Asked Questions

Are these o-rings suitable for fuel systems?
Yes. The Viton FKM compound is formulated to resist petroleum, diesel and fuel blends, making these o-rings appropriate for many fuel system sealing points.

Do the dimensions follow a standard size?
Yes. The o-ring is offered to AS568-type dimensions with actual measured values of 2.350 in ID, 2.770 in OD and 0.210 in cross-section for predictable fit.

What temperatures can these o-rings handle?
They operate from -26C (-15F) up to 232C (450F), suitable for many high-heat engine and process applications.