Mr O-Ring 260 Viton O-Ring 90A Durometer, 6-1/2 in ID Pack of 10

In this review the Mr O-Ring 260 Viton O-Ring is judged as a reliable, application-ready sealing option for technicians and hobbyists who need a small, durable kit of Viton seals. The bottom line: this pack of 10 90A durometer Viton o-rings is best for users who require chemical and high-temperature resistance in a standard AS568 size, because the material and hardness deliver broad compatibility from fuels to silicone oils while holding shape under heat. The review focuses on real-world sealing needs rather than aesthetic packaging or retail extras.

Key Features

• Material and resistance: Made from 260 Viton (fluorocarbon rubber), these o-rings resist fuels, oils, aromatics and many chemicals for dependable seals in harsh environments.
• Temperature range: Rated from -26C (-15F) to 232C (450F), they handle both low-temperature service and very high temp air applications without rapid degradation.
• Durometer hardness: 90A durometer provides a firm sealing surface that maintains integrity under compression and repeated cycles, useful for hydraulic or fuel system fittings.
• Dimensional accuracy: Nominal and actual dimensions are provided (6-1/2 in ID nominal; 6.484 in actual), which helps installers choose a close match for AS568-size replacements.
• Pack quantity and shelf life: Supplied as a pack of 10 with effectively unlimited shelf-life, making it practical to stock spares for maintenance or multiple projects.

Who It's For

The product is aimed at mechanics, maintenance technicians, and DIYers who need a resilient o-ring for petroleum products, fuels blended with methanol or ethanol, diesel or biodiesel, and many oils and greases. It is also a good choice for systems exposed to ozone, weather, or elevated temperatures where a standard elastomer would fail.

Those who should look elsewhere include users requiring very soft seals for light compression (lower durometer than 90A) or applications that demand food-grade or potable-water certification, since this is an industrial-grade Viton o-ring intended for chemical and high-temp resistance rather than regulatory drinking-water use.

Pros & Cons

Pros

• Excellent chemical compatibility with fuels, oils, hydraulic fluids and many solvents due to the fluorocarbon formulation.
• High temperature tolerance up to 232C (450F) for applications subjected to heat or hot air.
• Accurate sizing with both nominal and actual dimensions listed, easing replacement of AS568 sizes.
• Supplied as a pack of 10 and stable on the shelf, suitable for maintenance inventories.

Cons

• At 90A hardness the o-ring is relatively firm, which may not seal optimally in low-pressure or delicate soft-seal requirements.

Specifications

Material	260 Viton (FKM)
Durometer	90A
Nominal dimensions	6-1/2 in ID, 6-3/4 in OD, 1/8 in CS
Actual dimensions	6.484 in ID, 6.762 in OD, 0.139 in CS
Metric dimensions	164.69 mm ID, 171.75 mm OD, 3.53 mm CS
Temperature range	-26C (-15F) to 232C (450F)
Pack quantity	10 o-rings

Our Verdict

The Mr O-Ring 260 Viton 90A o-ring pack is a practical, value-minded choice for professionals and hobbyists who need robust chemical and high-temperature resistance in a standard AS568 size. It is especially useful for fuel, oil and high-temp sealing tasks where durability matters, though users needing softer, low-pressure seals or specific potable-water approvals should consider alternatives.

Frequently Asked Questions

Are these o-rings compatible with gasoline and diesel?
Yes. The Viton formulation is designed to perform well with petroleum products, gasoline blends and diesel, including some biodiesel blends.

Will the 90A hardness work for static and dynamic seals?
90A is suitable for many static and some dynamic sealing applications; it provides firm compression resistance but may be less ideal where a very soft, low-pressure seal is required.

Do these o-rings have an expiration date?
No. The product is listed with effectively unlimited shelf-life, so they can be stored as spares without a fixed expiration.