{"product_id":"275in-buna-n-o-ring-cord-stock-70a-durometer-500-ft-spool","title":".275in Buna-N O-Ring Cord Stock 70A Durometer - 500 ft spool","description":"\u003cp\u003eIn this review of the.275in Buna-N O-Ring Cord Stock, the bottom line is simple: this is a workhorse sealing material for projects that need reliable oil and hydrocarbon resistance. The reviewer found the 70A durometer and round cross-section well suited to cutting replacement o-rings, tyre repairs on small wheels, and custom seals for hydraulic and pneumatic fittings. Made in the U. S. A., the 500 ft spool offers long runs for frequent users, and its compatibility with common petroleum and vegetable oils is the single biggest reason to choose it for industrial and hobby sealing tasks.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Buna-N (Nitrile) provides good resistance to petroleum, HFA\/HFB\/HFC fluids and aliphatic hydrocarbons for confident use around oils and fuels.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHardness:\u003c\/strong\u003e The 70A durometer balances flexibility and firmness, making the cord easy to glue and form into replacement o-rings while holding shape under compression.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature range:\u003c\/strong\u003e Rated for a wide range of service temperatures so it performs in cold conditions down to around -40 degrees F and up to about 212 degrees F for many applications.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLength and format:\u003c\/strong\u003e The 500 ft spool supplies enough cord for many cuts and projects, reducing waste and repeated purchases for shops and maintenance teams.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDurability:\u003c\/strong\u003e Buna-N offers abrasion and tear resistance with useful compression set characteristics for repeated sealing cycles.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMade in the U. S. A.:\u003c\/strong\u003e Domestic manufacture ensures consistent quality control and predictable material properties for professional use.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eWho It's For\u003c\/h2\u003e\u003cp\u003eThis cord stock is ideal for maintenance engineers, hobbyists, and small fabricators who need a reliable o-ring cord for making custom seals, repairing rubber tires on small equipment, or producing gasketing for fluid-handling parts. The spool format suits users who will cut many rings or need continuous lengths.\u003c\/p\u003e\u003cp\u003eIt is less suitable for applications exposed to strong ozone, UV sunlight, or solvents like acetone and certain ethers and esters; users requiring long-term outdoor weathering resistance or compatibility with aggressive ketones should consider alternate elastomers.\u003c\/p\u003e\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eGood compatibility with petroleum and many hydraulic fluids, making it practical for oil-handling systems.\u003c\/li\u003e\n\u003cli\u003e70A durometer offers a useful balance of resilience and ease of assembly when forming rings or bonding with adhesive.\u003c\/li\u003e\n\u003cli\u003eLarge 500 ft spool delivers strong value for shops and repeat consumers who cut many seals.\u003c\/li\u003e\n\u003cli\u003eCustomers report strong fit, adhesive ease, and long-term durability in routine use.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNot recommended for prolonged exposure to ozone, UV light, or certain solvents such as acetone and some esters.\u003c\/li\u003e\n\u003cli\u003eTemperature limits mean extreme high-heat applications above the rated range may require a different compound.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eSpecifications\u003c\/h2\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003eBuna-N (Nitrile, NBR)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCross-section\u003c\/td\u003e\n\u003ctd\u003eRound cord\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal thickness\u003c\/td\u003e\n\u003ctd\u003e0.275in (1\/4in nominal, 7 mm)\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\u003eLength\u003c\/td\u003e\n\u003ctd\u003e500 ft spool\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature range\u003c\/td\u003e\n\u003ctd\u003eApprox -40 degrees F to 212 degrees F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eMade in the U. S. A.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch2\u003eOur Verdict\u003c\/h2\u003e\u003cp\u003eThe.275in Buna-N O-Ring Cord Stock is a practical, cost-effective choice for making replacement o-rings and custom seals when resistance to oils and common hydraulic fluids is required. For shops and hobbyists who cut many rings, the 500 ft spool and 70A firmness offer reliable performance and good adhesive compatibility, making it a strong value for general industrial sealing needs.\u003c\/p\u003e\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eIs this cord compatible with hydraulic oil?\u003c\/strong\u003e\u003cbr\u003eYes, Buna-N is compatible with many petroleum-based hydraulic fluids and HFA\/HFB\/HFC types listed for typical nitrile use.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use this outdoors?\u003c\/strong\u003e\u003cbr\u003eIt can be used outdoors for short periods, but prolonged exposure to UV and ozone will degrade the material, so a UV-stable compound is better for long-term outdoor service.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill it bond well with adhesives?\u003c\/strong\u003e\u003cbr\u003eCustomers report that the 70A durometer bonds easily with common rubber adhesives, making it straightforward to form glued o-rings and repairs.\u003c\/p\u003e","brand":"Mr O-Ring","offers":[{"title":"Default Title","offer_id":48749502071003,"sku":"B00QVB52B4","price":448.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/815SybkGjpL._SL1500_df5a8a1c-de36-4c3f-8a0c-1a07f62dbfb9.jpg?v=1778765296","url":"https:\/\/gearmusthave.com\/products\/275in-buna-n-o-ring-cord-stock-70a-durometer-500-ft-spool","provider":"GearMustHave","version":"1.0","type":"link"}