Mr O-Ring 447 Viton O-Ring 90A Durometer, 9 in ID - Pack of 10

In this review the Mr O-Ring 447 Viton O-Ring pack is evaluated for professionals and DIYers who need high-temperature and chemical-resistant seals. The bottom line: this set of ten 90A durometer Viton o-rings is best for applications exposed to fuels, mineral oils, silicone greases and high heat where long-term stability matters. Its nominal 9 in ID and 1/4 in cross-section follow common AS568 sizing, and the material properties give confidence in demanding sealing tasks rather than disposable, low-performance uses.

Key Features

• Material: Viton FKM provides robust resistance to high temperature, ozone and many organic solvents, keeping seals reliable in harsh environments.
• Durometer: The 90A hardness balances flexibility and compression resistance, preserving sealing performance under pressure and repeated cycles.
• Dimensions: Nominal 9 in ID, 9-1/2 in OD and 1/4 in cross-section match AS568 sizing for straightforward replacement and fitment.
• Temperature range: Rated from -26C to 232C so these o-rings work across low to very high temperature applications without rapid degradation.
• Chemical compatibility: Performs well in petroleum, fuels, biodiesel blends, methanol or ethanol blends, and many oils and greases, reducing the need for specialized seals.
• Packaging: Sold as a pack of 10, which is practical for maintenance kits or multiple installation points.

Who It's For

This product suits maintenance technicians, industrial seal shops, and serious DIYers who replace o-rings in engines, pumps, or hydraulic components where exposure to fuels, oils and elevated temperatures is expected. The 90A durometer and Viton chemistry make it appropriate for applications that demand chemical resistance and dimensional stability.

Those who should look elsewhere include users needing food-grade elastomers, extreme low-temperature elastomers beyond the stated range, or softer compound o-rings for very low compression force requirements; this 90A hardness is not ideal for ultra-soft sealing needs.

Pros & Cons

Pros

• High chemical and heat resistance thanks to Fluorocarbon Viton material for long service life in harsh conditions.
• Pack of 10 provides spare parts for routine maintenance and multiple assemblies.
• AS568-compatible nominal sizing simplifies replacement in standard grooves and housings.
• Wide temperature range supports both elevated and moderate low-temperature operations.

Cons

• The 90A durometer is relatively hard, so it may not seal as well in applications that require softer, more conformable o-rings.
• Not intended for food-contact or applications requiring specialty non-fluorocarbon materials.

Specifications

Material	Viton (FKM)
Durometer	90A
Nominal Dimensions	9 in ID, 9-1/2 in OD, 1/4 in CS
Actual Dimensions	8.975 in ID, 9.525 in OD, 0.275 in CS
Metric Dimensions	227.97 mm ID, 241.95 mm OD, 6.99 mm CS
Temperature Range	-26C (-15F) to 232C (450F)
Pack Size	10 o-rings

Our Verdict

The Mr O-Ring 447 Viton 90A o-ring pack is a practical, cost-effective option for industrial and maintenance users who need reliable chemical and heat resistance. Its AS568-compatible sizing and broad temperature range make it a good value for replacing seals exposed to fuels, oils and high temperatures, while those needing softer or food-safe materials should consider alternatives.

Frequently Asked Questions

Are these o-rings compatible with fuel and biodiesel?
Yes. The Viton material is specified to perform well with petroleum fuels and diesel blends, including biodiesel mixes.

Do these o-rings meet a standard size?
The nominal dimensions follow AS568 sizing conventions so they are suitable for common standard grooves and replacement needs.

What temperature range can they handle?
They are rated from -26C (-15F) up to 232C (450F), suitable for many high-temperature sealing applications.