{"product_id":"mr-o-ring-424-viton-o-ring-4-3-8in-id-90a-durometer-pack-of-5","title":"Mr O-Ring 424 Viton O-Ring 4-3\/8in ID 90A Durometer - Pack of 5","description":"\u003cp\u003eIn this review the focus is on a practical, high-temperature sealing option: the Mr O-Ring 424 Viton O-Ring pack of 5. The bottom line is that this kit is aimed at technicians and hobbyists who need a durable Fluorocarbon (FKM) seal that resists fuels, oils and high heat. The single biggest reason to buy is the material and hardness combination - a 90A durometer Viton that reliably withstands temperatures up to 232C (450F) and exposure to petroleum products, making it suitable for automotive, industrial and chemical-use sealing tasks.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n \u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Made from Viton (Fluorocarbon rubber FKM) which provides excellent resistance to fuels, hydraulic fluids and many organic solvents.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eTemperature range:\u003c\/strong\u003e Rated from -26C (-15F) to 232C (450F), giving confidence for high-temperature applications and hot-fluid exposure.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eDurometer hardness:\u003c\/strong\u003e The 90A hardness offers a firm sealing surface that stays resilient under compression and repeated cycles.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eSize accuracy:\u003c\/strong\u003e Nominal dimensions 4-3\/8in ID, 4-7\/8in OD with actual dimensions close to spec (4.350in ID, 4.900in OD) for reliable fitting to standardized grooves.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eVersatile compatibility:\u003c\/strong\u003e Performs well in petroleum, diesel, biodiesel blends, methanol\/ethanol blends, mineral and silicone oils, and in ozone and weather-exposed environments.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eValue pack:\u003c\/strong\u003e Supplied as a pack of 5, useful for multiple repairs or spare parts inventory without needing to buy single units.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThis Viton o-ring pack is best for maintenance mechanics, fabricators and DIYers who work with engines, pumps and fittings where exposure to fuels, oils or high temperatures is expected. Its 90A hardness and FKM compound make it a solid choice for sealing applications in automotive, industrial hydraulic or chemical systems that require resistance to aromatics and solvents.\u003c\/p\u003e\n\u003cp\u003eThose who should look elsewhere include users needing very soft, low-compression-set seals (softer durometers) or applications that require food-grade or FDA-compliant elastomers, since this product is specified for chemical and temperature performance rather than food-contact certification.\u003c\/p\u003e\n\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 high-temperature resistance up to 232C (450F), suitable for hot-fluid seals.\u003c\/li\u003e\n \u003cli\u003eViton FKM formula gives strong chemical resistance to fuels, oils and many solvents.\u003c\/li\u003e\n \u003cli\u003ePack of 5 provides spare parts for repeated maintenance and reduces downtime.\u003c\/li\u003e\n \u003cli\u003eActual dimensions closely match nominal sizes, easing replacement with AS568-sized grooves.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n \u003cli\u003e90A is a relatively firm durometer, which may not seal well in applications that require very soft, conforming o-rings.\u003c\/li\u003e\n \u003cli\u003eNot specified for food or pharmaceutical contact, so unsuitable where those certifications are required.\u003c\/li\u003e\n\u003c\/ul\u003e\n\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 (Fluorocarbon rubber, 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\u003e4-3\/8in ID, 4-7\/8in OD, 1\/4in CS\u003c\/td\u003e\n\u003c\/tr\u003e\n \u003ctr\u003e\n\u003ctd\u003eActual dimensions\u003c\/td\u003e\n\u003ctd\u003e4.350in ID, 4.900in OD, 0.275in CS\u003c\/td\u003e\n\u003c\/tr\u003e\n \u003ctr\u003e\n\u003ctd\u003eMetric dimensions\u003c\/td\u003e\n\u003ctd\u003e110.49 mm ID, 124.47 mm OD, 6.99 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\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eThe Mr O-Ring 424 Viton o-ring pack is a practical, cost-effective choice for users who need a high-temperature, chemically resistant seal in automotive or industrial systems. Its 90A FKM compound and accurate sizing make it good value for maintenance kits and repair work, while the pack format keeps spares on hand for fast replacements.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eCan these o-rings handle fuel and oil exposure?\u003c\/strong\u003e\u003cbr\u003eYes. The Viton FKM compound is rated for petroleum products, diesel and biodiesel blends, and mineral and silicone oils.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat temperatures will these o-rings tolerate?\u003c\/strong\u003e\u003cbr\u003eThey are specified from -26C (-15F) up to 232C (450F), suitable for many high-temperature sealing environments.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAre these standard AS568 sizes?\u003c\/strong\u003e\u003cbr\u003eYes. The product meets size standards defined by AS568 and actual dimensions closely match the nominal sizes for reliable replacement.\u003c\/p\u003e","brand":"Mr O-Ring","offers":[{"title":"Default Title","offer_id":48232292352219,"sku":"B07R7429SW","price":64.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/51Kuv29LevL._SL1000_44728fe0-d420-4f4b-abaf-68d19c21ca51.jpg?v=1770836545","url":"https:\/\/gearmusthave.com\/products\/mr-o-ring-424-viton-o-ring-4-3-8in-id-90a-durometer-pack-of-5","provider":"GearMustHave","version":"1.0","type":"link"}