Mr O-Ring 430 Viton O-Ring 90A, 5-1/8in ID (Pack of 5)

In this review the Mr O-Ring 430 Viton O-Ring is evaluated for technicians and DIYers who need a durable, heat-resistant sealing solution. The bottom line: this pack of five 90A durometer Viton o-rings is best for applications exposed to fuels, oils, high temperatures or ozone where a tight, long-lasting seal is required. The reviewer found the material, nominal and actual dimensions, and broad chemical compatibility make these o-rings a reliable choice for plumbing, fuel systems, hydraulic fittings and equipment maintenance.

Key Features

• Material: 430 Viton (FKM) provides excellent resistance to fuels, oils and many chemicals, reducing seal failure in aggressive environments.
• Hardness: 90A durometer delivers a firm seal that resists extrusion and maintains shape under compression in demanding assemblies.
• Temperature range: Rated from -26C to 232C (-15F to 450F), so the o-ring works in both cold starts and high temperature operation.
• Pack size: Sold as a pack of 5, which is convenient for routine maintenance and small repair jobs without buying bulk quantities.
• Size accuracy: Nominal and actual dimensions are listed, helping match replacements precisely to worn parts and preventing fit issues.
• Standards: Sized to meet AS568 standards, making it straightforward to swap into common industry grooves and housings.

Who It's For

This o-ring is aimed at mechanics, HVAC and plumbing technicians, and equipment maintainers who encounter fuels, hydraulic fluids, or high temperature applications and need a dependable sealing element. Its resistance to petroleum, biodiesel blends, methanol or ethanol blends, and most organic solvents makes it suited to automotive and industrial use.

Those working exclusively with low-temperature elastomers for extremely flexible seals, or applications requiring food-grade or medical-grade elastomers, should look for specialized compounds instead; the Viton FKM material is engineered for chemical and thermal resistance rather than food safety or maximum softness.

Pros & Cons

Pros

• Excellent chemical and high temperature resistance from the 430 Viton compound.
• 90A durometer balances firmness and sealing capability to resist extrusion in many assemblies.
• Pack of 5 provides a practical supply for repairs and routine maintenance.
• Actual and metric dimensions are provided for accurate replacements.

Cons

• Not intended for food or medical use where specific certifications are required.
• Higher hardness may be less forgiving in applications that require a very soft gasket feel.

Specifications

Our Verdict

The Mr O-Ring 430 Viton 90A, 5-1/8in ID pack of 5 is a practical, value-minded choice for maintenance work that requires chemical and thermal resilience. It is worth buying for automotive, hydraulic, and industrial sealing tasks because the material and size information support accurate replacements and long service life under demanding conditions.

Frequently Asked Questions

Are these o-rings compatible with diesel and biodiesel?
Yes, the 430 Viton compound is specified to perform well with diesel and blends including biodiesel.

Will the 90A hardness work for high temperature applications?
Yes, the 90A Viton is rated to 232C (450F) and retains sealing properties across that temperature range.

Do these meet standard sizing for replacements?
The product is offered to AS568 size standards and includes both nominal and actual dimensions for accurate matching.