377 Viton O-Ring 75A, 10 in ID x 10-3/8 in OD - Durable Chemical Seal

In this review the 377 Viton O-ring is judged as a practical replacement seal for technicians, hobbyists, and equipment maintainers who need a resilient, heat- and fuel-resistant gasket. The bottom line: this pack of ten black, round-section O-rings delivers reliable leak resistance in applications that see fuels, aromatic and aliphatic hydrocarbons, silicone oil, and high temperatures up to 400 degrees F, making it a go-to option when chemical compatibility and heat tolerance matter most.

Key Features

• Material: Made of Viton fluorocarbon elastomer, the compound provides strong resistance to fuels and many chemicals so seals last longer under exposure.
• Temperature range: Rated from -15 degrees F to 400 degrees F, the O-ring handles a broad band of operating temperatures for engine and industrial use.
• Hardness: With a 75A shore durometer, the ring resists penetration and maintains shape under compression, helping preserve sealing integrity.
• Cross-section: The round profile forms a positive seal between overlapping cylindrical surfaces for common plumbing and hydraulic joints.
• Pack size: Supplied as a pack of ten, it offers spare parts on hand for routine maintenance and replacements.

Who It's For

The 377 Viton O-ring suits mechanics, field technicians, and laboratory staff who routinely service fuel systems, hydraulic fittings, or equipment exposed to heat and aggressive fluids. Users replacing worn seals on fuel bottles, barrels, or specialty fittings will appreciate the fit, chemical compatibility, and leak resistance customers report.

Those who should look elsewhere include users needing compatibility with strong alkalis, ammonia, or glycol-based brake fluids, since Viton is vulnerable to those media; also choose a different elastomer if extreme low-temperature flexibility below -15 degrees F is required.

Pros & Cons

Pros

• Excellent chemical and fuel resistance for broad industrial use.
• High temperature capability to 400 degrees F preserves sealing under heat.
• Durable 75A hardness that customers note holds up well and resists wear.
• Value-packed set of ten makes routine maintenance simple and cost effective.

Cons

• Not compatible with low molecular weight organic acids, strong alkalis, or glycol-based brake fluids, so chemical limitations apply.
• Durometer 75A is firm; may be less suitable where an ultra-soft, conforming seal is required.

Specifications

Our Verdict

The 377 Viton O-ring is a solid, practical choice for anyone needing a heat- and fuel-resistant replacement seal; it offers dependable leak resistance and durability at a reasonable per-part cost. Buy these if you need chemical compatibility with fuels and hydrocarbons and want spares on hand; avoid them only when compatibility with alkalis or specialty fluids is required.

Frequently Asked Questions

Can these O-rings handle fuel exposure?
Yes, Viton is compatible with many fuels, aromatic and aliphatic hydrocarbons, and silicone oil, making these suitable for fuel-system seals.

What temperatures will they withstand?
They are suitable from -15 degrees F to 400 degrees F, covering most engine and industrial operating ranges.

Are these rings compatible with brake fluid or ammonia?
No, Viton is vulnerable to glycol-based brake fluids, ammonia gas, and strong alkalis, so do not use them with those media.