Mr O-Ring 357 Viton O-Ring 90A Durometer - Pack of 10

In this review the Mr O-Ring 357 Viton O-Ring is evaluated for workshop and industrial sealing needs; the bottom line is simple: these are a reliable choice when chemical and high-temperature resistance matter. The reviewer found the 90A durometer compound and Viton (FKM) material deliver stable sealing across fuels, mineral oils and many solvents, while the nominal 5-1/2' ID size fits common AS568-compatible grooves. For mechanics, fabricators and maintenance techs who need a durable, small-batch supply, this pack of 10 provides consistent dimensions and long shelf-life without surprises.

Key Features

• Material: Viton FKM gives strong resistance to high temperature, ozone and many chemicals for durable sealing performance.
• Hardness: The 90A durometer balances firmness and compression recovery, helping maintain a tight seal in static and some dynamic applications.
• Size accuracy: Nominal 5-1/2' ID with actual dimensions listed ensures better fitment when matching AS568 sizes in existing housings.
• Temperature range: Rated from -26C to 232C (-15F to 450F), suitable for high-temp engines, ovens and heated lines.
• Chemical compatibility: Performs well with petroleum fuels, biodiesel blends, methanol or ethanol blends, oils and many solvents, reducing failure risk in aggressive environments.
• Pack quantity: Sold as a pack of 10, giving spare parts on hand for routine maintenance and repair tasks.

Who It's For

This product is best for industrial maintenance staff, automotive technicians and small shops that service fuel systems, hydraulic connections or high-temperature equipment and need a compact, reliable stock of Viton o-rings. The chemical resistance and wide temperature range make it especially useful where exposure to fuels, mineral oil or high heat is expected.

Those working exclusively with very soft sealing needs, food-grade applications requiring specific approvals, or sizes outside the AS568 range should look elsewhere; likewise, users needing elastomers softer than 90A or with different material approvals may prefer alternative compounds.

Pros & Cons

Pros

• Excellent chemical and high-temperature resistance from the Viton (FKM) compound.
• Consistent 90A durometer hardness for dependable sealing performance in many static applications.
• Pack of 10 gives convenient supply for repairs and maintenance tasks.
• Sizes listed with actual and metric dimensions help verify fit before installation.

Cons

• 90A durometer is relatively firm, so it may not be ideal for applications needing very soft compression seals.
• No food-grade or specialty approvals are indicated, limiting use in regulated food or medical environments.

Specifications

Our Verdict

The Mr O-Ring 357 Viton 90A pack of 10 is a practical, good-value option for technicians and maintenance teams who need chemical- and heat-resistant seals in common AS568 sizes. Its consistent dimensions, high-temperature tolerance and broad compatibility with fuels and oils make it a dependable stock item, though buyers needing softer elastomers or specialty approvals should consider alternatives.

Frequently Asked Questions

Are these o-rings compatible with fuels and biodiesel blends?
Yes; the Viton FKM compound is specified to perform well with petroleum fuels, methanol or ethanol blends and diesel or biodiesel blends.

What temperature range can these o-rings handle?
They are rated from -26C (-15F) up to 232C (450F), suitable for many high-temperature sealing applications.

Do these follow AS568 sizing?
Yes; the product is listed to meet size standards defined by AS568 and includes both nominal and actual dimensions for verification.