Mr O-Ring 218 Viton O-Ring 90A, 1-1/4 in ID - Pack of 50

In this review the Mr O-Ring 218 Viton O-Ring is evaluated for workshops, maintenance shops and industrial users who need high-temperature, chemical-resistant seals in quantity. The bottom line: this pack of 50 Viton o-rings is a practical, cost-effective choice when you need consistent, high-durometer sealing material that resists fuels, oils and heat. The reviewer found the 90A durometer and actual nominal-to-actual sizing to be reliable for static and light dynamic seals, and the wide temperature range makes these o-rings suitable for demanding environments.

Key Features

• Material: Viton (FKM) offers exceptional resistance to high temperature and many chemicals, which keeps seals intact where other rubbers fail.
• Hardness: The 90A durometer provides a firm seal that resists extrusion and deformation under pressure while maintaining sealing contact.
• Size accuracy: Nominal 1-1/4 in ID and 1-1/8 in cross-section match closely to actual dimensions for predictable fit in standard AS568 grooves.
• Temperature range: Rated from -26C (-15F) to 232C (450F), these o-rings handle hot engine bays and high-temperature processing without rapid degradation.
• Chemical compatibility: Performs well with petroleum, diesel and biodiesel blends, methanol or ethanol blends, silicone oils, and many organic solvents, reducing the need for multiple material types.
• Pack size: A pack of 50 supplies routine maintenance needs and reduces frequent reordering for shops with ongoing seal replacement.

Who It's For

These o-rings are best for maintenance technicians, HVAC and automotive professionals, and industrial users who require robust seals that tolerate heat, oils and common fuels. The pack size and consistent 90A hardness make them suited to preventive maintenance kits or small production runs.

Those needing ultra-soft seals for delicate, low-pressure applications or specialized compounds with extreme acid resistance beyond general chemical exposure should look at other elastomers. Also, if a precise metric nominal is mandatory rather than AS568 sizing, confirm fit before large purchases.

Pros & Cons

Pros

• High chemical and heat resistance extends service life in aggressive environments.
• 90A durometer gives a reliable, firm seal that resists extrusion and retains shape.
• Actual dimensions closely match nominal sizes for predictable installation in standard grooves.
• Bulk pack of 50 is economical for shops and maintenance teams.

Cons

• 90A is relatively hard, so it may not be ideal where a softer, more compliant seal is required.
• Not all niche chemicals are covered; verify compatibility for specialized solvents.

Specifications

Our Verdict

The Mr O-Ring 218 Viton o-ring pack is a smart buy for technicians and small shops that need durable, heat- and chemical-resistant seals in quantity. Its 90A hardness and close actual-to-nominal sizing make installation predictable and reliable, offering good value compared with single-piece sourcing. Choose these when you need bulk, high-performance Viton o-rings for routine maintenance and industrial sealing tasks.

Frequently Asked Questions

Are these o-rings compatible with fuels?
Yes; they perform well with petroleum, gasoline blends, diesel and biodiesel blends, as well as with methanol or ethanol blends in typical sealing applications.

Will the 90A hardness work for dynamic seals?
90A is suitable for many light dynamic and static sealing tasks, but for high-speed dynamic shafts you may prefer a softer compound designed for dynamic wear.

How long do these o-rings last in storage?
The material has an unlimited shelf-life when stored away from direct sunlight and excessive ozone, per the product information.