{"product_id":"238-viton-o-ring-75a-3-1-2-in-id-3-3-4-in-od-pack-of-25","title":"238 Viton O-Ring 75A, 3-1\/2 in ID 3-3\/4 in OD (Pack of 25)","description":"\u003cp\u003eIn this review the focus is on the 238 Viton O-ring pack and why it suits technicians, hobbyists, and maintenance teams needing reliable seals for fuel, chemical and high-temperature applications. The bottom line: these black Viton rings deliver durable sealing performance across a wide temperature range and resist many fuels and solvents, making them a practical replacement part for cylinders and bottle seals where heat and chemical exposure are concerns. The pack of 25 also makes it easy to keep spares on hand for routine maintenance or field repairs.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Made from Viton fluorocarbon elastomer, the O-ring offers strong resistance to heat, fuels and many chemicals commonly found in industrial settings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature range:\u003c\/strong\u003e Rated to perform from -15 degrees F to 400 degrees F, the ring maintains sealing ability in both cold starts and hot operating conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHardness:\u003c\/strong\u003e The 75A shore durometer provides a good balance of flexibility and resistance to penetration for reliable static seals.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCross-section:\u003c\/strong\u003e The round cross-section creates a dependable seal between cylindrical overlapping surfaces such as bottle collars and barrel fittings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Suitable for non-flammable hydraulic fuels, silicone oil, chlorinated and aromatic hydrocarbons, as well as vacuum and outdoor exposure scenarios.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eWho It's For\u003c\/h2\u003e\u003cp\u003eThese O-rings are best for maintenance technicians, plumbing and hydraulic specialists, firearms and suppressor owners, and anyone who needs replacement seals for fuel bottles or cylindrical joints that face heat or fuel exposure. The pack quantity and standard sizing make them convenient for shops that perform frequent replacements.\u003c\/p\u003e\u003cp\u003eThose who should look elsewhere include users who require compatibility with strong alkalis, ammonia gas, amines, glycol-based brake fluids, or super-heated steam, since Viton is vulnerable to those substances. If an application demands extreme flexibility below -26 degrees C or immersion in aggressive acids, a different elastomer may be a better choice.\u003c\/p\u003e\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eExcellent heat and fuel resistance that holds up under high temperatures and hot components.\u003c\/li\u003e\n\u003cli\u003ePack of 25 offers clear value for frequent replacements and maintenance spares.\u003c\/li\u003e\n\u003cli\u003eCustomers report accurate fit and reliable leak resistance in common uses such as fuel bottles and barrel seals.\u003c\/li\u003e \u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNot suitable for exposure to low molecular organic acids, ammonia, alkalis or glycol-based brake fluids.\u003c\/li\u003e\n\u003cli\u003eThe 75A hardness may feel too firm for some dynamic sealing applications that need softer seals.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eSpecifications\u003c\/h2\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart\u003c\/td\u003e\n\u003ctd\u003e238 Viton O-ring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003eViton (fluorocarbon elastomer)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eColor\u003c\/td\u003e\n\u003ctd\u003eBlack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e3-1\/2 in ID, 3-3\/4 in OD, 1\/8 in width\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDurometer\u003c\/td\u003e\n\u003ctd\u003e75A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature range\u003c\/td\u003e\n\u003ctd\u003e-15 degrees F (-26 degrees C) to 400 degrees F (205 degrees C)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQuantity\u003c\/td\u003e\n\u003ctd\u003ePack of 25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch2\u003eOur Verdict\u003c\/h2\u003e\u003cp\u003eThe 238 Viton O-ring pack is a dependable, cost-effective option for anyone needing robust static seals exposed to heat, fuels, or common hydrocarbons. With a practical size, 75A hardness and a broad temperature range, it is a smart buy for maintenance shops and users replacing bottle and barrel seals, provided the application does not involve known Viton incompatibilities.\u003c\/p\u003e\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eCan these O-rings be used with gasoline and aromatic fuels?\u003c\/strong\u003e\u003cbr\u003eYes; Viton is compatible with many fuels and aromatic hydrocarbons, making these rings suitable for fuel-facing seals.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eAre they suitable for high vacuum systems?\u003c\/strong\u003e\u003cbr\u003eYes; Viton can be used in high vacuum environments, though installation and cleanliness affect performance.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill these resist ozone and weathering outdoors?\u003c\/strong\u003e\u003cbr\u003eYes; Viton has good ozone and weathering resistance for outdoor exposure within the specified temperature range.\u003c\/p\u003e","brand":"Mr O-Ring","offers":[{"title":"Default Title","offer_id":48184985321691,"sku":"B000FMWQ3M","price":53.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/81iyYJCP7YL._SL1500_04ac8189-b39b-4407-b31e-5105b0675f9d.jpg?v=1769477166","url":"https:\/\/gearmusthave.com\/products\/238-viton-o-ring-75a-3-1-2-in-id-3-3-4-in-od-pack-of-25","provider":"GearMustHave","version":"1.0","type":"link"}