Mr O-Ring 270 Viton O-Ring 90A Durometer 9 in ID Pack of 5

In this review the Mr O-Ring 270 Viton O-Ring is presented for technicians and hobbyists who need a high-temperature, fuel-resistant seal in a commonly used size. The bottom line: it is a dependable, purpose-built o-ring designed to meet AS568 sizing and to resist fuels, oils and high heat. Reviewers will appreciate that the 90A durometer Viton compound balances firmness with sealing reliability, and the pack of five gives spare parts for installations or maintenance.

Key Features

• Material: 270 Viton (FKM) offers excellent resistance to fuels, mineral oils and many organic solvents for long service life.
• Temperature range: Rated from -26C (-15F) to 232C (450F), it works in high-temperature environments where many elastomers fail.
• Size accuracy: Nominal 9 in ID, 9-1/4 in OD and 1/8 in cross-section with actual measured dimensions very close to nominal for reliable fit.
• Durometer: The 90A hardness provides a firm seal that resists extrusion while still conforming to sealing surfaces under compression.
• Packed quantity: Comes as a pack of 5, giving spares for installation, testing or replacement without buying multiple single units.

Who It's For

The Mr O-Ring 270 Viton is best for maintenance technicians, hydraulic and fuel system mechanics, and industrial users who require a durable, high-temperature o-ring in AS568-equivalent sizes. It is suited to applications exposed to petroleum products, diesel blends, methanol or ethanol blends, greases and high vacuum environments.

Users who need extremely soft seals for low-pressure pneumatic systems or who require FDA food-grade certification should look elsewhere, since this product is focused on chemical and thermal resistance rather than food contact compliance.

Pros & Cons

Pros

• Excellent chemical resistance to fuels, oils and many solvents thanks to the Viton (FKM) compound.
• Wide operating temperature range suitable for high-heat applications up to 232C (450F).
• Accurate sizing and AS568-compliant dimensions make replacement straightforward in standard grooves.
• Pack of five provides spare parts for repairs and reduces downtime.

Cons

• At 90A durometer the o-ring is relatively firm, which may be less ideal for low-pressure seals that need a softer material.

Specifications

Our Verdict

The Mr O-Ring 270 Viton 90A in the 9 in size is a practical choice for users who need a heat- and fuel-resistant seal that matches AS568 sizing. It is good value for maintenance and industrial work where chemical resistance and temperature tolerance matter, and the pack of five reduces the need to reorder frequently.

Frequently Asked Questions

Is this o-ring suitable for fuel systems?
Yes, the Viton (FKM) compound performs well with petroleum fuels, diesel and fuel blends.

Will the 90A hardness seal low-pressure applications?
The 90A durometer is relatively firm; it seals well under compression but softer compounds may be better for very low-pressure or delicate seals.

Does it conform to standard sizes?
Yes, the o-ring meets AS568-equivalent dimensions and the actual measurements closely match the nominal size.