{"product_id":"mr-o-ring-249-viton-o-ring-90a-durometer-4-7-8-in-id-pack-of-10","title":"Mr O-Ring 249 Viton O-Ring 90A Durometer 4-7\/8 in ID Pack of 10","description":"\u003cp\u003eIn this review the Mr O-Ring 249 Viton O-ring is examined for technicians and maintenance pros who need a resilient, fuel-resistant seal in bulk quantities. The bottom line: this pack of 10 90A durometer Viton o-rings is aimed at applications exposed to high temperatures, fuels and mineral oils where chemical resistance matters most. The reviewer found the nominal 4-7\/8 in ID size and the 90A hardness make these rings a practical choice for industrial sealing tasks, especially where compatibility with petroleum, diesel blends, and high heat is required.\u003c\/p\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Viton (fluorocarbon rubber) delivers strong resistance to high temperature, ozone and many organic solvents, which reduces seal failures in harsh environments.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHardness:\u003c\/strong\u003e 90A durometer gives a firm cross-section that resists extrusion and retains shape under compression in demanding mechanical seals.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature range:\u003c\/strong\u003e Rated from -26C (-15F) to 232C (450F), allowing use across cold starts and very high operating temperatures without rapid degradation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChemical compatibility:\u003c\/strong\u003e Performs well with petroleum products, fuels blended with methanol or ethanol, diesel and biodiesel blends, mineral and silicone oils and greases.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e Nominal 4-7\/8 in ID, 5-1\/8 in OD, 1\/8 in cross-section with precise actual measures for tighter fit in replacement jobs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePack quantity:\u003c\/strong\u003e Supplied as a pack of 10, which suits maintenance shops and repeat service intervals without frequent reordering.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThe Mr O-Ring 249 Viton o-ring is best for maintenance technicians, hydraulic and pneumatic service shops, and hobbyists who repair fuel systems, pumps or high-temperature equipment and need a reliable, fuel-resistant seal. Its bulk pack of 10 keeps spare parts on the shelf for recurring service jobs or installations that use standardized AS568 sizes.\u003c\/p\u003e\n\u003cp\u003eThose who should look elsewhere include users needing extreme flexibility at very low temperatures below -26C, or applications that require a softer durometer for delicate, low-force seals; in those cases a silicone or lower-hardness elastomer would be more appropriate.\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\u003eExcellent chemical and heat resistance from Viton material reduces replacement frequency in fuel-exposed systems.\u003c\/li\u003e\n\u003cli\u003e90A durometer provides firmness against extrusion and is suitable for many industrial sealing tasks.\u003c\/li\u003e\n\u003cli\u003eAccurate actual dimensions (4.859 in ID, 5.137 in OD, 0.139 in CS) make replacements straightforward for matching AS568 sizes.\u003c\/li\u003e\n\u003cli\u003ePack of 10 offers good value for shops and repeat maintenance needs.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eHigher durometer means it is less supple than softer o-rings, which can be a limitation for low-pressure, delicate sealing surfaces.\u003c\/li\u003e\n\u003cli\u003eNot suited for extreme cold below the specified -26C range.\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\u003eViton (FKM)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDurometer\u003c\/td\u003e\n\u003ctd\u003e90A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal dimensions\u003c\/td\u003e\n\u003ctd\u003e4-7\/8 in ID, 5-1\/8 in OD, 1\/8 in CS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eActual dimensions\u003c\/td\u003e\n\u003ctd\u003e4.859 in ID, 5.137 in OD, 0.139 in CS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature range\u003c\/td\u003e\n\u003ctd\u003e-26C (-15F) to 232C (450F)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePack quantity\u003c\/td\u003e\n\u003ctd\u003e10 o-rings\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eThe Mr O-Ring 249 Viton 90A o-ring is a solid choice for plumbers, mechanics and maintenance teams who need durable, fuel-resistant seals in a common AS568 size. It offers strong chemical and temperature resistance and comes in a practical pack of 10, making it good value for industrial or repeated service use, while users requiring softer or extreme-cold elastomers should consider alternative compounds.\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eAre these o-rings compatible with gasoline and diesel?\u003c\/strong\u003e\u003cbr\u003eYes; the Viton material is rated for petroleum products, gasoline blends and diesel, including some biodiesel blends.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDo the listed sizes match AS568 standards?\u003c\/strong\u003e\u003cbr\u003eYes; the product is intended to meet AS568 size definitions with nominal and actual dimension data provided for fitting.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow long will these o-rings store on the shelf?\u003c\/strong\u003e\u003cbr\u003eViton has an unlimited shelf-life when stored properly away from extreme heat and direct sunlight.\u003c\/p\u003e","brand":"Mr O-Ring","offers":[{"title":"Default Title","offer_id":48239539552475,"sku":"B07R74ZV4V","price":41.79,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/51Kuv29LevL._SL1000_221ac527-0d91-4725-be8e-69ff87428b88.jpg?v=1770959945","url":"https:\/\/gearmusthave.com\/products\/mr-o-ring-249-viton-o-ring-90a-durometer-4-7-8-in-id-pack-of-10","provider":"GearMustHave","version":"1.0","type":"link"}