{"product_id":"750-in-buna-n-o-ring-cord-stock-70a-10-ft-piece","title":".750 in Buna-N O-Ring Cord Stock 70A - 10 ft Piece","description":"\u003cp\u003eIn this review of the.750 in Buna-N O-Ring Cord Stock the bottom line is simple: this 70A nitrile cord is best for workshop repairs and fluid-resistant seals where durability and chemical compatibility matter. The reviewer found it particularly useful for replacing worn rubber parts and fabricating custom o-rings because the cord is dense, easy to cut, and bonds well with common adhesives. Its temperature range and resistance to petroleum-based fluids make it a practical choice for hydraulic, pneumatic, and general industrial maintenance tasks.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Buna-N (nitrile) offers reliable resistance to petroleum, HFA, HFB, and HFC fluids, making it suitable for many hydraulic and fuel-related uses.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHardness:\u003c\/strong\u003e The 70A durometer delivers a balance of flexibility and firmness that holds shape well in seals while still compressing for a tight fit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature Range:\u003c\/strong\u003e Rated for a wide working range, the cord performs across common shop temperatures from cold starts to warm operating conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMade in USA:\u003c\/strong\u003e Domestic manufacture ensures consistent quality and predictable material properties for repeat projects.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLength and Cross Section:\u003c\/strong\u003e Supplied as a 10 ft piece in a round cross section, it is convenient for cutting multiple custom o-rings or repair segments without seams.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eWho It's For\u003c\/h2\u003e\u003cp\u003eThis Buna-N cord is aimed at technicians, machinists, and hobbyists who need a durable, petroleum-resistant sealing material for custom o-rings, tire repairs, or gasket rebuilding. It is also a good fit for maintenance shops that frequently work on hydraulic or pneumatic systems and require consistent hardness and adhesion properties.\u003c\/p\u003e\u003cp\u003eThose who need resistance to ozone, sunlight, or aggressive solvents such as acetone and esters should look elsewhere, since Buna-N is vulnerable to ozone, UV exposure, and certain solvents. For high-heat applications above the stated range or for ozone\/UV-exposed outdoor seals, a different elastomer is recommended.\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 chemical compatibility with petroleum and many hydraulic fluids, making it reliable for equipment service.\u003c\/li\u003e\n\u003cli\u003eDurable 70A hardness that balances wear resistance and sealability for many common applications.\u003c\/li\u003e\n\u003cli\u003eEasy to cut and glue, so fabricating and repairing custom o-rings is straightforward.\u003c\/li\u003e\n\u003cli\u003eSold as a 10 ft piece and made in the USA, providing value and consistent quality.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNot suitable for prolonged ozone or UV exposure, so outdoor or electrical-motor environments are a limitation.\u003c\/li\u003e\n\u003cli\u003eSome customers reported mixed results on exact leak resistance depending on application and fit.\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\u003eDurometer\u003c\/td\u003e\n\u003ctd\u003e70A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCross Section\u003c\/td\u003e\n\u003ctd\u003eRound cord, 0.750 in thickness\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLength\u003c\/td\u003e\n\u003ctd\u003e10 ft piece\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Range\u003c\/td\u003e\n\u003ctd\u003e-40 degrees F to 212 degrees F (-40 C to 100 C)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChemical Compatibility\u003c\/td\u003e\n\u003ctd\u003ePetroleum, HFA, HFB, HFC fluids, vegetable oil, alcohol, acids, aliphatic hydrocarbons\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.750 in Buna-N O-Ring Cord Stock is a practical, cost-effective choice for workshop repairs and fluid-exposed seals where petroleum resistance and a 70A hardness are required. It is particularly good value for those who need a reliable 10 ft supply for multiple custom rings or repairs, but users with ozone, UV, or aggressive solvent exposure should select a different material.\u003c\/p\u003e\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eIs this cord compatible with hydraulic fluids?\u003c\/strong\u003e\u003cbr\u003eYes, Buna-N is compatible with many petroleum-based hydraulic fluids including HFA, HFB, and HFC types.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan it be used outdoors in sunlight?\u003c\/strong\u003e\u003cbr\u003eNo, Buna-N is vulnerable to ozone and UV, so it is not recommended for prolonged outdoor sun exposure.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat size and length is supplied?\u003c\/strong\u003e\u003cbr\u003eThe product is a round cord 0.750 in thick supplied as a 10 ft piece.\u003c\/p\u003e","brand":"Mr O-Ring","offers":[{"title":"Default Title","offer_id":48640213876955,"sku":"B00QVB49M2","price":90.19,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/712mL2CVl4L._SL1500_22339dc4-2ef0-4b11-8b34-6e35f01a5175.jpg?v=1778737680","url":"https:\/\/gearmusthave.com\/products\/750-in-buna-n-o-ring-cord-stock-70a-10-ft-piece","provider":"GearMustHave","version":"1.0","type":"link"}