Mr O-Ring 330 Viton O-Ring 90A Durometer 2-1/8in ID Pack of 10

In this review the Mr O-Ring 330 Viton O-Ring (pack of 10) is evaluated for technicians and hobbyists who need a high-temperature, fuel-resistant seal in a common AS568 size. The bottom line: this 90A durometer Viton o-ring stands out for chemical and thermal resilience, making it a practical choice where fuel, oil, or elevated temperature exposure is expected. The review focuses on real-world sealing performance, dimensional accuracy, and material suitability so you can decide if this pack of 10 fits your maintenance or repair needs.

Key Features

• Material: Fluorocarbon rubber (Viton/FKM) offers exceptional resistance to high temperatures, ozone, weather and many organic solvents, so seals hold up in harsh conditions.
• Durometer: 90A hardness provides a firm sealing surface that resists extrusion while still compressing enough to form reliable static and low-dynamic seals.
• Size accuracy: Nominal and actual dimensions are closely matched to AS568 sizing, which helps replacement installs fit into existing grooves without modification.
• Chemical compatibility: Performs well with petroleum fuels, diesel blends, methanol/ethanol blends, hydraulic fluids and many oils, reducing downtime from seal failures in these media.
• Temperature range: Rated from -26C (-15F) to 232C (450F), enabling use in both cold starts and very high temperature applications where many elastomers would soften or crack.
• Pack size: Sold as a pack of 10, making it easy to stock common replacement parts for workshop maintenance or multiple assembly points.

Who It's For

This product suits mechanics, HVAC and hydraulic technicians, and fabricators who need durable, fuel- and oil-resistant seals in the AS568 size equivalent to 2-1/8in ID. The firm 90A durometer is particularly beneficial where extrusion resistance and dimensional stability matter, such as static face seals, fuel system components, and some high-temperature housings.

It may be less suitable for extremely dynamic rotary shaft seals that require lower durometer compounds for flexibility, or for applications requiring FDA-grade elastomers; in those cases users should choose a different material or hardness designed for continuous dynamic movement or food contact.

Pros & Cons

Pros

• Excellent chemical and high-temperature resistance reduces replacement frequency in fuel and oil-exposed systems.
• 90A hardness provides strong extrusion resistance and stable sealing under compression.
• Dimensional specs list both nominal and actual dimensions, helping installers confirm fit before use.
• Pack of 10 is convenient for maintenance kits or multiple repairs.

Cons

• Higher 90A durometer is less flexible than softer o-rings, so it is not ideal for highly dynamic rotary seals requiring more pliability.

Specifications

Material	Viton (Fluorocarbon rubber, FKM)
Durometer	90A
Nominal dimensions	2-1/8in ID, 2-1/2in OD, 3/16in CS
Actual dimensions	2.100in ID, 2.520in OD, 0.210in CS
Metric dimensions	53.34 mm ID, 64.00 mm OD, 5.33 mm CS
Temperature range	-26C (-15F) to 232C (450F)
Pack quantity	10

Our Verdict

The Mr O-Ring 330 Viton 90A o-ring pack is a sensible choice for anyone needing a robust, fuel- and heat-resistant replacement in the AS568 size family. It delivers reliable chemical compatibility and dimensional accuracy at a reasonable value, especially for maintenance shops and technicians who keep spares on hand. Choose a different hardness only if you need greater flexibility for continuous dynamic sealing.

Frequently Asked Questions

Are these o-rings compatible with gasoline and diesel?
Yes, the Viton compound is formulated to perform well with petroleum fuels, diesel and common fuel blends including methanol or ethanol mixes.

Will the 90A hardness work for my rotating shaft seal?
90A is relatively firm and better suited to static seals or low-dynamic applications; for continuous rotary shafts a softer compound is often preferred for flexibility.

Do these meet an AS568 size standard?
Yes, the product is designed to meet size standards defined by AS568 and lists both nominal and actual dimensions for verification.