Mr O-Ring 341 Viton O-Ring 90A Durometer - Pack of 10

In this review the Mr O-Ring 341 Viton O-Ring is assessed for workshop and industrial sealing needs; it is aimed at technicians, mechanics, and maintenance buyers who need a durable, heat-resistant sealing solution. The bottom line: this 90A durometer Viton o-ring delivers reliable chemical and temperature resistance that performs well in petroleum, fuel blends, mineral oils and many solvents, making it a practical choice when longevity and compatibility matter most.

Key Features

• Material: Viton (FKM) offers excellent resistance to high temperature, ozone and weather for longer service life in harsh environments.
• Durometer: The 90A hardness provides a firmer seal that resists extrusion and deformation under pressure compared with softer compounds.
• Size accuracy: Nominal and actual dimensions are provided so users can match fittings precisely for dependable sealing without guesswork.
• Chemical compatibility: Performs well with petroleum products, fuels blended with methanol or ethanol, diesel and biodiesel blends, and many oils and greases.
• Temperature range: Rated from -26C (-15F) to 232C (450F) so it is suited to both low-temperature and very high-temperature applications.
• Pack quantity: Supplied as a pack of 10 so small maintenance shops and field technicians can replace multiple seals without frequent reordering.

Who It's For

The 341 Viton o-ring is best for professional users who need a compact, high-temperature resistant seal for hydraulic, fuel system or industrial equipment where compatibility with hydrocarbons and solvents is critical. It is also suitable for laboratory or vacuum applications that require reliable sealing under heat and chemical exposure.

It is less appropriate for users who need a very soft, low-durometer seal for delicate applications or for systems that require FDA food-grade elastomers; those buyers should look for lower durometer or food-compatible materials.

Pros & Cons

Pros

• Excellent chemical and high-temperature resistance from the Viton (FKM) compound.
• Accurate nominal and measured dimensions reduce installation uncertainty and leakage risk.
• 90A hardness resists extrusion and maintains shape in demanding service conditions.

Cons

• Higher durometer means it may not seal as well in low-compression or very small-gap applications compared with softer o-rings.

Specifications

Our Verdict

The Mr O-Ring 341 Viton o-ring is a solid, economical choice for maintenance and industrial sealing when chemical resistance and high temperature performance matter. Buyers who need a firmer, long-lived seal for petroleum, fuel blends and many solvents will find good value in this pack of 10; those needing softer, food-grade elastomers should consider alternatives.

Frequently Asked Questions

Is this o-ring compatible with diesel and biodiesel blends?
Yes, the Viton compound is formulated to perform well with diesel and biodiesel blends as noted in the compatibility information.

What is the usable temperature range for this o-ring?
The specified temperature range is -26C (-15F) up to 232C (450F), suitable for many high-temperature applications.

Are the actual dimensions different from the nominal dimensions?
Yes; the listing provides both nominal and measured sizes so installers can confirm fit: actual ID 3.475 in, OD 3.895 in, CS 0.210 in.