377 Viton O-Ring 90A, 10 in ID, Pack of 5 - High Temp Seal

In this review of the 377 Viton O-Ring from Mr O-Ring, the bottom line is simple: this pack of five 90A durometer o-rings is aimed at technicians and hobbyists who need reliable seals that resist fuels, oils and high temperatures. The reviewer found these rings well suited for demanding sealing tasks where chemical resistance and temperature stability matter, and notes the nominal 10 in ID sizing that aligns with common AS568 standards. If you need a compact pack of durable Viton o-rings for petroleum and high-temp service, this is worth considering.

Key Features

• Material: Viton (FKM) construction provides strong resistance to fuels, mineral oils and many organic solvents, reducing seal failure in chemical environments.
• Hardness: 90A durometer gives a firm cross-section that holds shape under compression and is suitable for static and some dynamic sealing.
• Size accuracy: Nominal dimensions 10 in ID, 10-3/8 in OD and 3/16 in CS with actual measurements listed, making it easier to match to existing grooved housings.
• Temperature range: Usable from -26C (-15F) up to 232C (450F), covering very high temperature air and many industrial fluids.
• Chemical versatility: Performs well with petroleum products, diesel and biodiesel blends, methanol or ethanol blends, silicone oils, and many acids, expanding application options.
• Pack size: Supplied as a pack of 5, convenient for repair jobs or stocking small maintenance kits.

Who It's For

This product is well suited to maintenance technicians, plumbers working with fuel lines, and engineers servicing pumps or hydraulic fixtures that require a temperature-resistant, chemical-compatible seal. The firmness of the 90A durometer and the Viton compound make it a strong choice where oil, fuel or heat exposure is expected.

Those who need the softest possible sealing for very low-pressure dynamic shafts or who require specialty elastomers for extreme low-temperature flexibility should look elsewhere. Also, buyers needing metric-only sizing or a single o-ring rather than a small pack might prefer a different SKU.

Pros & Cons

Pros

• Excellent chemical resistance to fuels, oils and many solvents, reducing maintenance frequency.
• Wide operating temperature range, suitable for high-temperature applications up to 232C (450F).
• Consistent 90A hardness provides dimensional stability and good sealing under compression.
• Pack of five offers value for repair work and small inventories.

Cons

• 90A durometer is relatively firm and may not be ideal for all dynamic shaft seals or ultra-low temperature flexibility needs.

Specifications

Brand	Mr O-Ring
Material	Viton (FKM)
Durometer	90A
Nominal Dimensions	10 in ID, 10-3/8 in OD, 3/16 in CS
Actual Dimensions	9.975 in ID, 10.395 in OD, 0.210 in CS
Temperature Range	-26C (-15F) to 232C (450F)
Pack Quantity	5 rings

Our Verdict

The 377 Viton O-Ring 90A in a pack of five is a practical, value-minded choice for professionals and DIYers who need durable seals that resist fuels, oils and high temperatures. Its consistent sizing, wide chemical compatibility and high temperature rating make it good value for maintenance tasks where longevity matters.

Frequently Asked Questions

Can these o-rings handle gasoline and diesel?
Yes, the Viton compound is rated for petroleum products including diesel and blends, making them suitable for fuel system seals.

Are the dimensions precise for replacement?
The listing provides nominal and actual dimensions so you can match against an existing seat; the rings conform to AS568 size standards for interchangeability.

What applications are best avoided?
Avoid using these if you require very soft elastomers for low temperature dynamic shafts or where extreme flexibility below -26C is necessary.