{"product_id":"o-ring-25x3-5","title":"O-ring 25x3.5 FS40, FS40C","description":"\u003ch1\u003eSTIHL O-Ring 25 x 3.5 - Genuine OEM Seal Ring\u003c\/h1\u003e\n\u003cp\u003eThe STIHL O-Ring 25 x 3.5 is a genuine OEM sealing ring designed to provide reliable leak protection in small engine assemblies, fuel systems and fluid connections across a wide range of STIHL outdoor power equipment. Manufactured from durable rubber compound material, this O-ring helps maintain dependable sealing performance under exposure to fuel, oil, vibration and temperature changes commonly found in professional and domestic handheld machinery.\u003c\/p\u003e\n\u003cp\u003eWith a precise 25 mm inner diameter and 3.5 mm cross-section, the STIHL O-Ring 25x3.5 fits accurately into matching grooves to support consistent sealing without distortion. The exact dimensions of 25 mm x 3.5 mm help maintain proper pressure retention in housings, caps, carburettor interfaces and line joints. Suitable for equipment including the STIHL FS 40, FS 40 C, MS 261, MS 500i and BR 600, this genuine seal ring helps reduce leaks, supports smoother engine operation and assists with long-term reliability during routine servicing and repairs.\u003c\/p\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eGenuine STIHL OEM O-ring for assured fit and sealing performance\u003c\/li\u003e\n\u003cli\u003eSize: 25 mm inner diameter x 3.5 mm cross-section\u003c\/li\u003e\n\u003cli\u003eDurable rubber construction designed for engine and fuel system environments\u003c\/li\u003e\n\u003cli\u003eHelps prevent fuel, oil and air leaks in compatible assemblies\u003c\/li\u003e\n\u003cli\u003eSupports reliable starting and smooth engine operation\u003c\/li\u003e\n\u003cli\u003eResistant to vibration, heat and outdoor operating conditions\u003c\/li\u003e\n\u003cli\u003eAccurate dimensions for dependable groove fitment and sealing integrity\u003c\/li\u003e\n\u003cli\u003eSuitable for chainsaws, trimmers, blowers, hedge trimmers and Kombi tools\u003c\/li\u003e\n\u003cli\u003eUseful replacement during servicing and preventative maintenance\u003c\/li\u003e\n\u003cli\u003eDesigned for repeatable OEM-quality sealing performance\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eTypical Applications\u003c\/h2\u003e\n\u003cp\u003eThis STIHL O-ring is commonly used to seal static and lightly dynamic joints in small engines and handheld outdoor power equipment. Typical uses include fuel system joints, carburettor interfaces, line unions, housing seals, pump seals and cover assemblies where reliable sealing is required to prevent leakage and maintain correct system pressure.\u003c\/p\u003e\n\u003cp\u003eThe 25 mm inner diameter and 3.5 mm profile make this seal suitable for many STIHL brushcutters, chainsaws, hedge trimmers, Kombi tools, blowers and cut-off machines operating in forestry, landscaping, grounds maintenance and domestic garden care applications.\u003c\/p\u003e\n\u003ch2\u003eTechnical Specification\u003c\/h2\u003e\n\u003cdiv style=\"overflow-x: auto;\"\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; text-align: left; border: 1px solid #ddd;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003eBrand\u003c\/th\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003eSTIHL\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003eProduct Type\u003c\/th\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003eO-Ring \/ Seal Ring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003eSize\u003c\/th\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003e25 mm x 3.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003eInner Diameter\u003c\/th\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003e25 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003eCross-Section\u003c\/th\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003e3.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003eMaterial\u003c\/th\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003eDurable rubber sealing compound\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003eManufacturer Part Number\u003c\/th\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003e9645 948 7734\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003eAlternate Part Numbers\u003c\/th\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 10px; text-align: left;\"\u003e9645-948-7734, 96459487734\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003ch2\u003eFits Models\u003c\/h2\u003e\n\u003cp\u003eCompatible with a wide range of STIHL equipment, including selected:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSTIHL FS 40 \u0026amp; FS 40 C brushcutters\u003c\/li\u003e\n\u003cli\u003eSTIHL FS 56, FS 70 and FS 90 series trimmers\u003c\/li\u003e\n\u003cli\u003eSTIHL KM KombiSystem engines\u003c\/li\u003e\n\u003cli\u003eSTIHL BR 500, BR 550 and BR 600 blowers\u003c\/li\u003e\n\u003cli\u003eSTIHL MS 171, MS 181, MS 261 and MS 500i chainsaws\u003c\/li\u003e\n\u003cli\u003eSTIHL HS hedge trimmers\u003c\/li\u003e\n\u003cli\u003eSTIHL HT pole pruners\u003c\/li\u003e\n\u003cli\u003eAdditional compatible STIHL models listed in manufacturer parts documentation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eAlso Known As\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eSeal ring\u003c\/li\u003e\n\u003cli\u003eRubber sealing ring\u003c\/li\u003e\n\u003cli\u003eCircular gasket\u003c\/li\u003e\n\u003cli\u003eRound-section seal\u003c\/li\u003e\n\u003cli\u003eO-ring seal\u003c\/li\u003e\n\u003cli\u003eRing gasket\u003c\/li\u003e\n\u003cli\u003eFuel system O-ring\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWhy Choose Genuine STIHL Seals?\u003c\/h2\u003e\n\u003cp\u003eSmall sealing components play an important role in engine reliability and pressure retention. Genuine STIHL O-rings are manufactured to precise OEM tolerances, helping maintain the correct fit, compression and chemical resistance required for outdoor power equipment exposed to fuel, oil, vibration and varying operating temperatures.\u003c\/p\u003e\n\u003ch2\u003eComplete Your Kit\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/www.gustharts.com\/pages\/stihl-parts\"\u003eSTIHL Spare Parts\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/www.gustharts.com\/collections\/2-stroke-engine-oil\"\u003e2 Stroke Oil\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/www.gustharts.com\/collections\/chainsaw-files\"\u003eChainsaw Files\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/www.gustharts.com\/collections\/fuel-cans-oil-cans-spouts\"\u003eFuel \u0026amp; Oil Cans\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eExplore More\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/www.gustharts.com\/collections\/chainsaw-accessories\"\u003eChainsaw Accessories\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/www.gustharts.com\/collections\/brushcutter-line-heads-and-blades\"\u003eBrushcutter Heads \u0026amp; Blades\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/www.gustharts.com\/collections\/hedge-trimmer-accessories\"\u003eHedge Trimmer Accessories\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/www.gustharts.com\/collections\/blower-vac-accessories\"\u003eBlower Accessories\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eFAQs\u003c\/h2\u003e\n\u003ch3\u003eWhat size is this STIHL O-ring?\u003c\/h3\u003e\n\u003cp\u003eThis O-ring has a 25 mm inner diameter and a 3.5 mm cross-section.\u003c\/p\u003e\n\u003ch3\u003eWhat is this O-ring used for?\u003c\/h3\u003e\n\u003cp\u003eIt is used to seal fuel, oil and air connections in compatible STIHL outdoor power equipment.\u003c\/p\u003e\n\u003ch3\u003eIs this a genuine STIHL part?\u003c\/h3\u003e\n\u003cp\u003eYes, this is a genuine STIHL OEM sealing ring designed for compatible STIHL machines.\u003c\/p\u003e\n\u003ch3\u003eWhich STIHL tools can use this O-ring?\u003c\/h3\u003e\n\u003cp\u003eIt fits a wide range of STIHL chainsaws, trimmers, hedge trimmers, blowers and Kombi tools.\u003c\/p\u003e\n\u003ch3\u003eWhy replace a worn O-ring?\u003c\/h3\u003e\n\u003cp\u003eReplacing damaged O-rings helps prevent leaks, maintain pressure and support reliable engine performance.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"Stihl","offers":[{"title":"Default Title","offer_id":58067009569142,"sku":"ST-9645 948 7734","price":0.95,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0690\/6603\/1348\/files\/STIHL_genuine_spares_from_authorised_dealer.png?v=1775040092","url":"https:\/\/www.gustharts.com\/en-eu\/products\/o-ring-25x3-5","provider":"Gustharts","version":"1.0","type":"link"}