{"product_id":"mr-o-ring-391-epdm-o-ring-22in-id-pack-of-5-weather-resistant","title":"Mr O-Ring 391 EPDM O-Ring 22in ID, Pack of 5 - Weather Resistant","description":"\u003cp\u003eIn this review the Mr O-Ring 391 EPDM O-Ring (pack of 5) is evaluated for users who need reliable, weather-resistant sealing in plumbing, automotive, or industrial applications. The bottom line: this 70A durometer EPDM ring is best for installations that demand ozone, sunlight and heat resistance up to 125C while remaining flexible at low temperatures, offering consistent nominal and actual dimensions for predictable fits. It is a practical choice when long shelf-life and compatibility with water, brake fluids, dilute acids and steam are priorities.\u003c\/p\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial and Durometer:\u003c\/strong\u003e 70A EPDM compound provides a balance of flexibility and firmness that suits static and moderate dynamic seals.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNominal and Actual Size:\u003c\/strong\u003e Nominal 22in ID with precise actual measurements ensures a closer-than-average fit for applications requiring dimensional accuracy.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChemical Compatibility:\u003c\/strong\u003e Performs well with water, alcohols, ketones, dilute acids and alkalis, and phosphate ester based hydraulic fluids for broad use.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature Range:\u003c\/strong\u003e Rated from -55C to 125C for reliable sealing from cold environments up to high service temperatures.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDurability:\u003c\/strong\u003e Excellent resistance to ozone, sunlight and weathering gives confidence for outdoor or exposed installations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePack Size:\u003c\/strong\u003e Supplied as a pack of 5 to cover multiple seals or spares for maintenance tasks.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThis o-ring is aimed at maintenance technicians, plumbers, and DIYers who need a robust EPDM seal for water systems, brake fluid service, low-pressure hydraulic components, or outdoor equipment exposed to weather and ozone. Its 70A hardness and measured dimensions make it suitable where a predictable compression and seal profile matter.\u003c\/p\u003e\n\u003cp\u003eThose needing resistance to petroleum-based oils, aggressive hydrocarbons, or very high-pressure rotary seals should look elsewhere; EPDM is not recommended for general exposure to mineral oils and some non-polar solvents. If a softer or harder compound is required outside the 70A range, consider a different material or durometer.\u003c\/p\u003e\n\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eGood weather and ozone resistance, making it durable for outdoor use.\u003c\/li\u003e\n\u003cli\u003eWide usable temperature range from -55C to 125C for versatile deployments.\u003c\/li\u003e\n\u003cli\u003eAccurate actual dimensions (21.955in ID, 22.375in OD) reduce fit surprises during installation.\u003c\/li\u003e\n\u003cli\u003ePack of 5 provides spares for maintenance or multiple installations.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eNot compatible with many petroleum-based oils, so it is not universal for all automotive or industrial fluid systems.\u003c\/li\u003e\n\u003cli\u003e70A hardness may be firmer than desired for very low-pressure or delicate sealing surfaces.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eMr O-Ring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003e391 EPDM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDurometer\u003c\/td\u003e\n\u003ctd\u003e70A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal Dimensions\u003c\/td\u003e\n\u003ctd\u003e22in ID, 22-3\/8in OD, 3\/16in CS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eActual Dimensions\u003c\/td\u003e\n\u003ctd\u003e21.955in ID, 22.375in OD, 0.210in CS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMetric Dimensions\u003c\/td\u003e\n\u003ctd\u003e557.66 mm ID, 568.32 mm OD, 5.33 mm CS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Range\u003c\/td\u003e\n\u003ctd\u003e-55C to 125C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eThe Mr O-Ring 391 EPDM 70A in a pack of 5 is a strong, value-oriented choice for anyone needing weatherproof, ozone-resistant seals with accurate nominal and actual sizes. It is particularly good for water systems, low-pressure hydraulics and outdoor equipment, but those needing oil resistance or a different hardness should choose another compound.\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eAre these o-rings suitable for steam?\u003c\/strong\u003e\u003cbr\u003eYes, the material can handle steam exposure up to 204.4C in short-term conditions, though continuous high-temperature steam service should be evaluated case by case.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill these resist automotive brake fluid?\u003c\/strong\u003e\u003cbr\u003eThey are compatible with many automotive brake fluids and phosphate ester based hydraulic fluids as stated, making them suitable for related sealing tasks.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow long will they store without degrading?\u003c\/strong\u003e\u003cbr\u003eThese EPDM o-rings have an effectively unlimited shelf-life when stored away from direct sunlight and extreme temperatures.\u003c\/p\u003e","brand":"Mr O-Ring","offers":[{"title":"Default Title","offer_id":48616455110875,"sku":"B07R43K6XZ","price":98.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/51Kuv29LevL._SL1000_922bef0f-ec87-48e1-9e3e-af8bd7a5585c.jpg?v=1778442495","url":"https:\/\/gearmusthave.com\/products\/mr-o-ring-391-epdm-o-ring-22in-id-pack-of-5-weather-resistant","provider":"GearMustHave","version":"1.0","type":"link"}