172 Viton O-Ring 75A Durometer 8-1/4 in ID 8-7/16 in OD - Pack of 10

In this review the 172 Viton O-ring is assessed for workshops and field repairs where chemical and heat resistance matter most. The bottom line: this pack of 10, black Viton seals is best for technicians and hobbyists who need a dependable replacement O-ring that resists fuels and high temperatures; its biggest selling point is the Viton compound and 75A hardness that combine to hold seals under heat and contact with aromatic and aliphatic hydrocarbons. Customers who need wide temperature range performance and reliable leak resistance will find the value clear.

Key Features

• Material: Made of Viton fluorocarbon elastomer to provide strong resistance to fuels, oils, ozone and many chemicals.
• Temperature range: Usable from -15 degrees F to 400 degrees F so it performs across most workshop and field temperature conditions.
• Durometer: 75A hardness gives good penetration resistance and durability for dynamic and static sealing tasks.
• Cross-section: Round profile delivers a reliable seal between cylindrical overlapping surfaces to prevent leaks under pressure.
• Standard size: Sized to AS568A equivalent dimensions for straightforward replacement in common equipment that uses 8-1/4 in ID O-rings.

Who It's For

This pack is aimed at maintenance techs, propulsion and fuel-system mechanics, lab personnel, and outdoors equipment owners who need robust O-ring replacements for fittings exposed to fuels, silicone oils and aromatic hydrocarbons. It suits anyone servicing MSA fuel bottles, Remington 1100 barrel seals, Silencerco switchback components and similar gear noted by users.

Those who should look elsewhere include users needing compatibility with strong alkalis, ammonia gas, glycol-based brake fluids, or super-heated steam, since Viton can be vulnerable to those specific substances and extreme chemistries.

Pros & Cons

Pros

• Excellent chemical and fuel resistance for seal longevity in many applications.
• Wide usable temperature range that maintains performance from cold starts to high-heat environments.
• Good fit and leak resistance reported by customers when used as replacements in specific equipment.

Cons

• Not compatible with low molecular organic acids, strong alkalis, some amines and glycol-based brake fluids, limiting use in certain systems.

Specifications

Material	Viton (fluorocarbon elastomer)
Color	Black
Inner Diameter (ID)	8-1/4 in
Outer Diameter (OD)	8-7/16 in
Cross-section Width	3/32 in
Durometer	75A shore
Temperature Range	-15 degrees F to 400 degrees F

Our Verdict

The 172 Viton O-ring pack offers solid value for anyone who needs a dependable, heat- and fuel-resistant replacement in common cylindrical seals. Its 75A hardness and broad temperature tolerance make it a practical choice for maintenance and repair tasks, provided the system fluids are compatible with Vitons chemical profile.

Frequently Asked Questions

Are these O-rings suitable for fuel systems?
Yes, Viton is compatible with many fuels, aromatic and aliphatic hydrocarbons and is commonly used in fuel-system seals.

What temperatures can they handle?
They are usable roughly from -15 degrees F up to 400 degrees F for most sealing applications.

Will they resist all chemicals?
No, Viton resists many solvents and fuels but is vulnerable to low molecular organic acids, ammonia, alkalis, certain amines and glycol-based brake fluids.