Mr O-Ring 144 EPDM O-Ring 70A Durometer 2-1/2 in ID Pack of 100

In this review the Mr O-Ring 144 EPDM O-Ring pack is judged on durability and versatility for common sealing tasks; it is best for technicians and hobbyists who need a reliable, weather-resistant seal in quantity. The reviewer found the 70A durometer EPDM compound provides a firm but flexible seal across a wide temperature span, and the pack of 100 offers obvious value for repetitive maintenance or production use. For anyone needing consistent AS568-equivalent sizing and resistance to ozone, sunlight and many dilute chemicals, this kit solves everyday sealing needs without fuss.

Key Features

• Material and Durometer: 70A EPDM compound balances elasticity and firmness so seals remain pliable without extruding under light compression.
• Size Accuracy: Nominal and actual dimensions are listed, which helps installers choose a close fit for existing grooves and housings.
• Chemical Resistance: Good performance in alcohols, dilute acids and alkalis, brake fluid and many polar solvents reduces unexpected failures in mixed-fluid environments.
• Temperature Range: Rated from -55C to 125C, making these o-rings suitable for both low-temperature flexibility and many warm service applications.
• Quantity Pack: Pack of 100 delivers cost-effective coverage for maintenance shops and repeated replacement schedules.
• Shelf Stability: An unlimited shelf-life claim means spares can be stored without worry about premature degradation.

Who It's For

These o-rings are aimed at maintenance technicians, plumbing or hydraulic service teams and DIYers who need a large supply of consistent, weather-resistant seals. The 70A hardness and EPDM chemistry suit outdoor equipment, water systems, steam applications and many automotive or industrial uses where ozone, sunlight and age resistance matter.

Those who need oil-specific elastomers (for prolonged contact with petroleum-based lubricants) or extremely high-temperature silicone compatibility should look elsewhere, since EPDM is optimized for polar fluids and has different limits than specialty rubber compounds.

Pros & Cons

Pros

• Durable EPDM compound resists ozone, sunlight and weathering for outdoor or exposed seals.
• Wide operating temperature range keeps flexibility at low temperatures and stability in warm service.
• Pack of 100 provides economical spares for shops and repeat repairs.
• Clear actual and metric dimensions make selection and cross-referencing straightforward.

Cons

• EPDM is not ideal for prolonged contact with petroleum-based oils, so performance can be limited in oil-heavy applications.
• The fixed 70A hardness may not suit applications that require either a much softer or much harder seal.

Specifications

Material	EPDM
Durometer	70A
Nominal Dimensions	2-1/2 in ID, 2-11/16 in OD, 3/32 in CS
Actual Dimensions	2.487 in ID, 2.693 in OD, 0.103 in CS
Metric Dimensions	63.17 mm ID, 68.41 mm OD, 2.62 mm CS
Temperature Range	-55C to 125C (-67F to 257F)
Quantity	Pack of 100

Our Verdict

The Mr O-Ring 144 EPDM 70A pack is a practical choice for workshops and maintenance crews who need reliable, weather-resistant seals in volume. Its documented dimensions, broad chemical resistance to polar fluids and long temperature tolerance make it good value for water, steam and outdoor applications; however, shops that work primarily with petroleum oils should select an oil-compatible compound instead.

Frequently Asked Questions

Are these o-rings suitable for steam service?
Yes; the EPDM material is listed as performing in steam up to 204.4C (400F) for many applications, and the specified temperature rating supports hot-service use within limits.

Do these match AS568 sizes?
Yes; the product meets size standards defined by AS568 and includes both nominal and actual dimensions for confirmation.

How long can these be stored before use?
The manufacturer indicates an unlimited shelf-life, so they can be held as spares without a defined expiry when stored properly.