Mr O-Ring 448 Viton O-Ring 90A Durometer - 9-1/2 in ID Pack of 10

In this review the focus is on a workhorse sealing option for industrial and plumbing needs: the Mr O-Ring 448 Viton O-Ring in a pack of 10. The bottom line is simple - this is for anyone who needs a reliable, high-temperature resistant o-ring that stands up to fuels, oils and harsh environments. The review highlights the o-ring's core strength: a 90A durometer Viton (FKM) compound that delivers broad chemical compatibility and a wide operating temperature range, making it a sensible choice for maintenance shops, equipment rebuilds, and fluid-handling systems.

Key Features

• Material and Hardness: Made from 90A durometer Viton (FKM), the compound offers strong resistance to high temperature, ozone and many chemicals, improving seal longevity in demanding conditions.
• Size Accuracy: Nominal 9-1/2 in ID and 10 in OD with actual dimensions very close to spec, which helps installers get correct fits without guesswork.
• Temperature Range: Rated -26C (-15F) to 232C (450F), so the o-ring works across low-temperature storage and very high operating temperatures.
• Chemical Compatibility: Performs well in petroleum products, diesel, biodiesel blends, methanol and ethanol blends, and many oils and solvents, reducing seal failure risk in fuel and lubrication systems.
• Pack Size: Supplied as a pack of 10, which suits technicians and shops that need multiple replacements on hand and reduces frequent reordering.

Who It's For

This o-ring is aimed at professionals and advanced DIY users who repair or maintain engines, pumps, valves and hydraulic components that see fuel, oil and high heat. The combination of Viton chemical resistance and a 90A hardness makes it appropriate where fuels, hydraulic fluids or high-temperature air are present.

Users who need soft seals for very light compression or food-grade elastomers should look elsewhere, since this product is a harder 90A industrial Viton and is not specified for food-contact or very low-pressure sealing where a softer rubber is required.

Pros & Cons

Pros

• Excellent resistance to fuels, oils and many solvents due to the Viton (FKM) compound.
• Wide operating temperature range suitable for high-heat applications.
• Pack of 10 provides practical value for maintenance and replacement cycles.
• Actual dimensions closely match nominal sizes for predictable installation.

Cons

• 90A hardness may be too firm for applications needing very soft or highly conforming seals.
• Not indicated for food-grade use or certain specialty chemical exposures not listed in the specification.

Specifications

Our Verdict

For maintenance pros and technicians who need a durable, high-temperature resistant sealing solution, the Mr O-Ring 448 in 90A Viton offers dependable chemical resistance and size accuracy at a reasonable value, especially in the pack-of-10 format. It is a practical buy when fuel and oil compatibility and high-temperature performance are priorities.

Frequently Asked Questions

Can these o-rings handle diesel and biodiesel blends?
Yes. The Viton compound is specified to perform well in diesel and blends with biodiesel, as well as petroleum-based fuels.

Are the actual dimensions reliable for replacement parts?
Yes. The product lists both nominal and actual dimensions, and the actual measurements closely match the nominal sizes for predictable fitting.

What temperature extremes are supported?
The o-ring is rated from -26C (-15F) up to 232C (450F), suitable for many low-temperature storage and very high operating temperature applications.