Mr O-Ring 441 Viton O-Ring 90A 7in ID Pack of 10 - High Temp Seal

In this review the Mr O-Ring 441 Viton O-Ring (90A, pack of 10) is evaluated for technicians and hobbyists who need small, reliable replacement seals that resist fuels, oils and high heat. The bottom line: this is a practical, utility-focused o-ring set for applications where chemical resistance and temperature stability matter most, and the review focuses on real-world fit, material behavior and the advantages of the 90A durometer Viton compound for demanding environments.

Key Features

• Material: The Viton fluorocarbon rubber formulation offers excellent resistance to fuels, mineral oils and many organic solvents so seals last longer in chemical service.
• Durometer: The 90A hardness balances elasticity and durability, providing a firm seal that resists extrusion in static and low-dynamic installations.
• Temperature range: Rated from -26C to 232C (-15F to 450F), the o-ring performs across a wide thermal span useful for engine compartments and heated process lines.
• Pack size: Supplied as a pack of 10, the set is convenient for maintenance kits and multiple replacement points without buying large quantities.
• Dimensional accuracy: Nominal and actual dimensions (7in ID nominal, actual 6.975in ID) provide close tolerances for predictable fit in AS568-equivalent grooves.

Who It's For

The 441 Viton o-ring is best for mechanics, plumbers and equipment maintainers who work with petroleum products, fuel blends, hydraulic fluids or areas exposed to high temperatures and ozone. Its combination of chemical resistance and 90A hardness suits applications such as fuel system seals, pump covers and static flange joints where durability is required.

Those needing extremely soft, low-pressure seals or food-grade elastomers should look elsewhere, since Viton 90A is a relatively firm fluorocarbon compound and is chosen mainly for chemical and heat resistance rather than for very low compression set or regulatory food-contact grades.

Pros & Cons

Pros

• High chemical resistance keeps seals intact in fuels, oils and many solvents.
• Wide usable temperature range supports applications from cold storage to elevated process temperatures.
• Consistent dimensional tolerances (actual vs nominal) make replacements straightforward.
• Pack of 10 provides immediate spare parts for routine maintenance.

Cons

• At 90A durometer the o-ring is relatively firm and may not be ideal for very low-pressure sealing or where extreme flexibility is required.

Specifications

Material	Viton (FKM) fluorocarbon rubber
Durometer	90A
Nominal dimensions	7in ID, 7-1/2in OD, 1/4in CS
Actual dimensions	6.975in ID, 7.525in OD, 0.275in CS
Metric dimensions	177.17 mm ID, 191.15 mm OD, 6.99 mm CS
Temperature range	-26C (-15F) to 232C (450F)
Quantity	Pack of 10

Our Verdict

The Mr O-Ring 441 Viton 90A pack of 10 is a strong choice for anyone who needs reliable chemical and heat-resistant seals without buying large volumes. It is good value for maintenance use and applications exposed to fuels, oils and high temperatures, provided a firmer 90A compound suits the sealing requirement rather than a softer elastomer.

Frequently Asked Questions

Are these o-rings compatible with diesel and biodiesel blends?
Yes, the Viton formulation is suited to diesel and common biodiesel blends and resists degradation from petroleum-based fuels.

Will the 90A hardness work for static flange seals?
The 90A durometer is appropriate for many static seals where extrusion resistance and durability are needed, though softer compounds may seal better in very low-pressure applications.

Do these meet standard AS568 sizes?
Yes, the product is offered to match AS568 size standards and lists both nominal and actual dimensions for reliable fitting.