{"product_id":"mr-o-ring-343-viton-o-ring-90a-durometer-pack-of-5","title":"Mr O-Ring 343 Viton O-Ring 90A Durometer - Pack of 5","description":"\u003cp\u003eIn this review the Mr O-Ring 343 Viton O-Ring is examined for technicians and DIYers who need a durable seal that handles fuels, oils and high heat. The bottom line: this 90A durometer Viton o-ring delivers predictable chemical and temperature resistance for demanding sealing tasks, and the pack of 5 makes it easy to keep spares on hand. Performance in petroleum, biodiesel blends, silicone oils and high-temperature applications is the single biggest reason a mechanic or maintenance pro will reach for this size.\u003c\/p\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Viton FKM construction gives excellent resistance to fuels, oils and many organic solvents, reducing seal failures in contact with aggressive fluids.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature range:\u003c\/strong\u003e Rated from -26C (-15F) to 232C (450F), it maintains sealing integrity across high-heat engine or industrial environments.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHardness:\u003c\/strong\u003e The 90A durometer provides a firm cross-section that resists extrusion while still compressing to form a reliable seal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize accuracy:\u003c\/strong\u003e Nominal and actual dimensions are provided so fit can be verified before installation, helping avoid returns or reorders.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVersatile compatibility:\u003c\/strong\u003e Performs well in petroleum, methanol or ethanol blends, biodiesel blends, mineral and silicone oils, ozone and weather exposure for broad application use.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity:\u003c\/strong\u003e Sold as a pack of 5, offering immediate spares for repairs or routine maintenance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThis o-ring is best for automotive technicians, small engine repair shops and industrial maintenance teams that need a compact, high-temperature resistant seal compatible with fuels, hydraulic fluids and many solvents. The firmness and Viton chemistry make it a solid choice where elevated temperature and chemical exposure are common.\u003c\/p\u003e\n\u003cp\u003eThose who need very soft seals for delicate instrumentation or who require food-grade elastomers should look elsewhere; Viton is not intended for food contact applications. Also, if a metric-native inventory or different durometer is required, pick a product sized or rated specifically for that use.\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 resistance to fuels, oils and many solvents, which reduces premature deterioration.\u003c\/li\u003e\n\u003cli\u003eHigh temperature capability up to 232C (450F) allows use near hot engine or process components.\u003c\/li\u003e\n\u003cli\u003e90A hardness resists extrusion and provides durable sealing under pressure.\u003c\/li\u003e\n\u003cli\u003ePack of 5 gives spare parts on hand for repairs or routine replacements.\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 makes it less suitable for applications needing a very soft, low-pressure seal.\u003c\/li\u003e\n\u003cli\u003eNot intended for food or beverage contact, limiting some sanitary uses.\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 size\u003c\/td\u003e\n\u003ctd\u003e3-3\/4 in ID, 4-1\/8 in OD, 3\/16 in CS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eActual dimensions\u003c\/td\u003e\n\u003ctd\u003e3.725 in ID, 4.145 in OD, 0.210 in CS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMetric dimensions\u003c\/td\u003e\n\u003ctd\u003e94.62 mm ID, 105.28 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-26C (-15F) to 232C (450F)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eThe Mr O-Ring 343 Viton 90A is a practical, cost-effective choice for mechanics and maintenance pros who need a heat- and chemical-resistant seal in a reliable AS568 size. Its durable 90A hardness and wide compatibility make it good value for industrial and automotive sealing tasks, and the five-pack format keeps spares on-hand for quick repairs.\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eIs this o-ring compatible with diesel and biodiesel blends?\u003c\/strong\u003e\u003cbr\u003eYes. The Viton formulation performs well with diesel and common biodiesel blends without rapid deterioration.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan it be used at high vacuum or ozone-exposed locations?\u003c\/strong\u003e\u003cbr\u003eYes. Viton offers good performance in high vacuum and resists ozone and weathering better than many elastomers.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the pack include five identical o-rings?\u003c\/strong\u003e\u003cbr\u003eYes. This listing supplies a pack of five identical Mr O-Ring 343 Viton o-rings for spare parts or multiple installations.\u003c\/p\u003e","brand":"Mr O-Ring","offers":[{"title":"Default Title","offer_id":48661250834651,"sku":"B07R74LBK5","price":36.29,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/51Kuv29LevL._SL1000_5bb73ec5-c284-44e1-bd1e-df6eabd71ab7.jpg?v=1778710224","url":"https:\/\/gearmusthave.com\/products\/mr-o-ring-343-viton-o-ring-90a-durometer-pack-of-5","provider":"GearMustHave","version":"1.0","type":"link"}