Mr O-Ring 4X465 Metric Viton O-Ring - 75A Durometer Seal

In this review the Mr O-Ring 4X465 Metric Viton O-Ring is evaluated for technicians and hobbyists who need a high-temperature, chemical-resistant sealing solution. The bottom line: this single-pack 465 mm ID, 4 mm cross-section o-ring stands out for its broad chemical compatibility and wide operating temperature range, making it a reliable choice where fuels, oils or elevated temperatures are involved. The review focuses on real-world sealing performance, material resilience and practical dimensions to help buyers confirm fit and suitability.

Key Features

• Material: Viton (FKM) construction provides excellent resistance to fuels, oils, ozone and many organic solvents for demanding environments.
• Temperature range: Rated from -26C to 232C (-15F to 450F), it handles both low-temperature exposure and sustained high-temperature service.
• Durability: 75A durometer hardness offers a good balance of flexibility and compression resistance for long-lasting seals under pressure.
• Exact sizing: Metric dimensions of 465 mm ID, 473 mm OD and 4 mm CS (actual approx 18.307 in ID, 18.622 in OD, 0.157 in CS) make it straightforward to confirm compatibility with existing grooves or housings.
• Chemical compatibility: Performs well in petroleum products, diesel and biodiesel blends, methanol or ethanol blends, silicone oil and hydraulic fluids for broad application use.
• Shelf life: Essentially unlimited shelf-life means spares can be stored long-term without accelerated degradation when kept properly.

Who It's For

This o-ring is aimed at maintenance technicians, industrial repair shops and DIYers who need a robust, high-temperature seal tolerant of fuels, oils and many solvents. It's particularly useful where metric sizing is required and where a 4 mm cross-section fits existing gland dimensions.

Those who need food-grade elastomers, extreme low-temperature specialty compounds beyond -26C, or a softer compound for very low compression force should consider alternate materials; similarly, users requiring metric sizes other than 465 mm ID should verify fit before purchase.

Pros & Cons

Pros

• Excellent chemical resistance thanks to the Viton FKM material, suitable for fuels and oils.
• Wide operating temperature range that covers many industrial and automotive applications.
• Accurate metric and imperial dimensions listed for easy verification of fit.
• Good hardness balance at 75A for durable sealing without excessive stiffness.

Cons

• Not intended for applications requiring food-grade or ultra-low temperature elastomers below -26C.

Specifications

Brand	Mr O-Ring
Material	Viton (FKM)
Durometer	75A
Metric Dimensions	465 mm ID, 473 mm OD, 4 mm CS
Imperial Dimensions	Approx 18.307 in ID, 18.622 in OD, 0.157 in CS
Temperature Range	-26C to 232C (-15F to 450F)
Pack Quantity	1

Our Verdict

The Mr O-Ring 4X465 is a pragmatic choice for users who need a durable, high-temperature and chemical-resistant seal in a metric size. Its Viton composition, accurate dimensions and balanced 75A hardness deliver reliable performance for industrial, automotive and hydraulic repairs, offering good value as a single spare or replacement piece.

Frequently Asked Questions

Is this o-ring suitable for fuel systems?
Yes. The Viton material is resistant to petroleum products, diesel and common fuel blends, making it appropriate for many fuel system sealing applications.

Will this o-ring handle high temperatures?
Yes. It is rated to 232C (450F) and will perform in high-temperature environments within that limit.

How do I confirm it will fit my groove?
Measure the inside diameter and cross-section of the existing groove and compare to the listed 465 mm ID and 4 mm CS (actual imperial equivalents provided) to ensure compatibility.