M5.7x134.6 Viton O-Ring 75A - Durable Chemical-Resistant Seal

In this review the M5.7x134.6 Viton O-Ring is evaluated for anyone needing a reliable, chemical-resistant seal in demanding environments. The bottom line: this pack of ten O-rings is best for technicians, hobbyists, and maintenance crews who require a compact, heat-tolerant gasket that resists fuels and many solvents. The reviewer found the most compelling reason to buy is the material choice - molded from Viton fluorocarbon elastomer - which delivers broad chemical compatibility and strong performance across high and low temperatures.

Key Features

• Material: Made from Viton for superior resistance to fuels, oils, and many solvents compared with general-purpose rubber.
• Hardness: A durometer of 75A gives a balance of flexibility and compression resistance for consistent sealing under load.
• Cross-section: The round cross-section creates a reliable seal between overlapping cylindrical surfaces in threaded or static joints.
• Temperature range: Rated for wide operating temperatures so it remains usable across cold starts and high-heat applications.
• Size pack: Supplied as a pack of ten, offering spare parts for multiple assemblies or replacements during maintenance.

Who It's For

This O-ring is aimed at users who need a small, dependable seal for hydraulic fittings, plumbing adapters, threaded barrel protectors, carburetor seat seals, or similar cylindrical joints. It suits mechanics and hobbyists who value chemical resistance and long life in contact with fuels, silicone oil, and many hydrocarbons.

Those who should look elsewhere include applications exposed to ammonia gas, strong alkalis, certain amines, glycol-based brake fluids, or prolonged super-heated steam, where Viton is vulnerable. If a softer Shore hardness is required for ultra-low compression force seals, consider a different durometer.

Pros & Cons

Pros

• Excellent chemical and fuel resistance for contact with non-flammable hydraulic fuels and aromatic or aliphatic hydrocarbons.
• Good thermal tolerance that keeps the seal intact through wide temperature swings.
• Balanced 75A hardness that provides dependable sealability and wear resistance for threaded protectors and valve seats.
• Pack of ten offers value and ready spares for repeat maintenance tasks.

Cons

• Not compatible with ammonia, strong alkalis, certain amines, glycol brake fluids, or super-heated steam, limiting use in some chemical systems.
• 75A hardness may be firmer than desired for extremely delicate low-force sealing needs.

Specifications

Material	Viton (fluorocarbon elastomer)
Color	Black
Inner Diameter (ID)	134.6 mm
Outer Diameter (OD)	146 mm
Cross-section / Width	5.7 mm (round)
Durometer	75A
Temperature Range	-15 degrees F (-26 degrees C) to 400 degrees F (205 degrees C)

Our Verdict

The M5.7x134.6 Viton O-Ring is a practical, value-minded choice for anyone needing a heat- and chemical-resistant seal in threaded or cylindrical assemblies. With its Viton construction and balanced 75A hardness, it delivers durable sealing for fuel, oil, and many solvent exposures while the pack of ten makes maintenance straightforward and cost effective.

Frequently Asked Questions

Is this O-ring compatible with gasoline and diesel?
Yes; Viton is compatible with many fuels and hydrocarbons, making it suitable for non-flammable hydraulic fuels and common fuel exposures.

Will it work at high temperatures?
Yes; the specified operating range covers up to about 400 degrees F (205 degrees C), so it handles many high-temperature applications.

Can I use it with brake fluid?
No; Viton is vulnerable to glycol-based brake fluids and is not recommended for prolonged exposure to those fluids.