{"product_id":"royal-enfield-1570197-c-cylinder-head-bolt-m10x181-classic-bullet-350","title":"Royal Enfield 1570197\/C – Cylinder Head Bolt M10 x 181mm (OEM) for Classic 350, Bullet 350, Hunter 350 J SERIES UK\/Euro V","description":"\u003cp data-start=\"360\" data-end=\"877\"\u003eKeep your cylinder head securely fastened with the genuine Royal Enfield \u003cstrong data-start=\"476\" data-end=\"520\"\u003e1570197\/C Cylinder Head Bolt (M10 × 181)\u003c\/strong\u003e. This OEM bolt is designed to factory tolerances in thread size, length, strength, and material (high-grade steel) to safely hold the cylinder head to the barrel under combustion pressures. If your existing bolt is rusty, stretched, damaged threads, or you’ve had cooling gasket leakage, this replacement restores proper sealing and structural integrity.\u003c\/p\u003e\n\u003cp data-start=\"879\" data-end=\"1340\"\u003eManufactured for Re’s newer 349cc J-Series single-cylinder engines, this M10 × 181 mm bolt is confirmed to fit \u003cstrong data-start=\"990\" data-end=\"1049\"\u003eClassic 350, Bullet 350, Hunter 350 (UK \/ Euro V trims)\u003c\/strong\u003e among others listed by Iron City Motorcycles. The bolt’s correct length (“181”) is critical—too short and you risk insufficient clamping; too long and it can bottom out or interfere. Sold as a single OEM bolt, this part ensures you get factory-specified thread pitch, coating, and strength.\u003c\/p\u003e\n\u003chr data-start=\"1342\" data-end=\"1345\"\u003e\n\u003cp data-start=\"1347\" data-end=\"1366\"\u003e\u003cstrong data-start=\"1347\" data-end=\"1364\"\u003eKey Features:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"1367\" data-end=\"1954\"\u003e\n\u003cli data-start=\"1367\" data-end=\"1491\"\u003e\n\u003cp data-start=\"1369\" data-end=\"1491\"\u003eGenuine Royal Enfield OEM \u003cstrong data-start=\"1395\" data-end=\"1427\"\u003e1570197\/C Cylinder Head Bolt\u003c\/strong\u003e – size \u003cstrong data-start=\"1435\" data-end=\"1450\"\u003eM10 x 181mm\u003c\/strong\u003e. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1492\" data-end=\"1596\"\u003e\n\u003cp data-start=\"1494\" data-end=\"1596\"\u003eFactory-grade material \u0026amp; coating to resist heat and corrosion. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003cspan class=\"ms-1 inline-flex max-w-full items-center relative top-[-0.094rem] animate-[show_150ms_ease-in]\" data-testid=\"webpage-citation-pill\"\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1597\" data-end=\"1699\"\u003e\n\u003cp data-start=\"1599\" data-end=\"1699\"\u003eExact bolt length and thread pitch for J-Series 349cc heads. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1700\" data-end=\"1821\"\u003e\n\u003cp data-start=\"1702\" data-end=\"1821\"\u003eCritical for proper clamping of cylinder head to barrel to prevent limp-engine, head gasket failure, or misalignment.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1822\" data-end=\"1917\"\u003e\n\u003cp data-start=\"1824\" data-end=\"1917\"\u003eOEM fitensures correct seating, torque spec compatibility, and improved engine reliability.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1918\" data-end=\"1954\"\u003e\n\u003cp data-start=\"1920\" data-end=\"1954\"\u003eSold individually (single bolt).\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"1956\" data-end=\"1959\"\u003e\n\u003cp data-start=\"1961\" data-end=\"2009\"\u003e\u003cstrong data-start=\"1961\" data-end=\"2009\"\u003eCompatibility Table :\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv class=\"_tableContainer_1rjym_1\"\u003e\n\u003cdiv class=\"group _tableWrapper_1rjym_13 flex w-fit flex-col-reverse\" tabindex=\"-1\"\u003e\n\u003ctable data-start=\"2011\" data-end=\"2537\" class=\"w-fit min-w-(--thread-content-width)\"\u003e\n\u003cthead data-start=\"2011\" data-end=\"2089\"\u003e\n\u003ctr data-start=\"2011\" data-end=\"2089\"\u003e\n\u003cth data-start=\"2011\" data-end=\"2019\" data-col-size=\"sm\"\u003eModel\u003c\/th\u003e\n\u003cth data-start=\"2019\" data-end=\"2044\" data-col-size=\"sm\"\u003eEngine Type \/ Platform\u003c\/th\u003e\n\u003cth data-start=\"2044\" data-end=\"2065\" data-col-size=\"sm\"\u003eEmissions \/ Region\u003c\/th\u003e\n\u003cth data-start=\"2065\" data-end=\"2089\" data-col-size=\"md\"\u003eYears \/ Trim \/ Notes\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody data-start=\"2108\" data-end=\"2537\"\u003e\n\u003ctr data-start=\"2108\" data-end=\"2272\"\u003e\n\u003ctd data-start=\"2108\" data-end=\"2136\" data-col-size=\"sm\"\u003eClassic 350 (UK \/ Euro V)\u003c\/td\u003e\n\u003ctd data-start=\"2136\" data-end=\"2153\" data-col-size=\"sm\"\u003e349cc J-Series\u003c\/td\u003e\n\u003ctd data-start=\"2153\" data-end=\"2174\" data-col-size=\"sm\"\u003eEuro V \/ UK market\u003c\/td\u003e\n\u003ctd data-start=\"2174\" data-end=\"2272\" data-col-size=\"md\"\u003eTrims like Dark Gunmetal, Stealth Black, Chrome Red etc. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"2273\" data-end=\"2400\"\u003e\n\u003ctd data-start=\"2273\" data-end=\"2300\" data-col-size=\"sm\"\u003eBullet 350 (UK \/ Euro V)\u003c\/td\u003e\n\u003ctd data-start=\"2300\" data-end=\"2317\" data-col-size=\"sm\"\u003e349cc J-Series\u003c\/td\u003e\n\u003ctd data-start=\"2317\" data-end=\"2331\" data-col-size=\"sm\"\u003eSame region\u003c\/td\u003e\n\u003ctd data-start=\"2331\" data-end=\"2400\" data-col-size=\"md\"\u003eStandard Black, Maroon etc. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-start=\"2401\" data-end=\"2537\"\u003e\n\u003ctd data-start=\"2401\" data-end=\"2428\" data-col-size=\"sm\"\u003eHunter 350 (UK \/ Euro V)\u003c\/td\u003e\n\u003ctd data-start=\"2428\" data-end=\"2445\" data-col-size=\"sm\"\u003e349cc J-Series\u003c\/td\u003e\n\u003ctd data-start=\"2445\" data-end=\"2459\" data-col-size=\"sm\"\u003eSame region\u003c\/td\u003e\n\u003ctd data-start=\"2459\" data-end=\"2537\" data-col-size=\"md\"\u003eDapper trims etc. listed by dealers. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003cspan class=\"ms-1 inline-flex max-w-full items-center relative top-[-0.094rem] animate-[show_150ms_ease-in]\" data-testid=\"webpage-citation-pill\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003chr data-start=\"2539\" data-end=\"2542\"\u003e\n\u003cp data-start=\"2544\" data-end=\"2559\"\u003e\u003cstrong data-start=\"2544\" data-end=\"2557\"\u003eVariants:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"2560\" data-end=\"2998\"\u003e\n\u003cli data-start=\"2560\" data-end=\"2766\"\u003e\n\u003cp data-start=\"2562\" data-end=\"2766\"\u003e\u003cstrong data-start=\"2562\" data-end=\"2587\"\u003ePart Number Variants:\u003c\/strong\u003e 1570197\/B vs 1570197\/C – both labelled “Bolt, Cylinder Head – M10 x 181”. The \/C version may have a different coating or revision than \/B. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2767\" data-end=\"2969\"\u003e\n\u003cp data-start=\"2769\" data-end=\"2969\"\u003e\u003cstrong data-start=\"2769\" data-end=\"2790\"\u003eFinish \/ Coating:\u003c\/strong\u003e Possibly different (e.g. zinc coated vs stainless \/ heat-treated) — \/C tends to show higher price, suggesting upgraded or revised version. \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2970\" data-end=\"2998\"\u003e\n\u003cp data-start=\"2972\" data-end=\"2998\"\u003e\u003cstrong data-start=\"2972\" data-end=\"2985\"\u003eQuantity:\u003c\/strong\u003e Single bolt.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"3000\" data-end=\"3003\"\u003e\n\u003cp data-start=\"3005\" data-end=\"3016\"\u003e\u003cstrong data-start=\"3005\" data-end=\"3014\"\u003eFAQs:\u003c\/strong\u003e\u003c\/p\u003e\n\u003col data-start=\"3018\" data-end=\"4553\"\u003e\n\u003cli data-start=\"3018\" data-end=\"3396\"\u003e\n\u003cp data-start=\"3021\" data-end=\"3396\"\u003e\u003cstrong data-start=\"3021\" data-end=\"3097\"\u003eHow can I check if 1570197\/C is the correct head bolt for my motorcycle?\u003c\/strong\u003e\u003cbr data-start=\"3097\" data-end=\"3100\"\u003e→ Remove the existing cylinder head bolt and inspect for markings (stamped number). Measure bolt length from under the head to end: it should be ~181 mm. Also check thread pitch \u0026amp; M10 head size. If your current bolt is marked 1570197\/B or 1570197\/C, and bolt geometry matches, \/C is correct.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3398\" data-end=\"3701\"\u003e\n\u003cp data-start=\"3401\" data-end=\"3701\"\u003e\u003cstrong data-start=\"3401\" data-end=\"3459\"\u003eWhat's the difference between 1570197\/B and 1570197\/C?\u003c\/strong\u003e\u003cbr data-start=\"3459\" data-end=\"3462\"\u003e→ Both are cylinder head bolts of the same thread and size. The difference is in “revision \/ finish \/ coating \/ batch revision” possibly offering improved durability or coating in \/C. \/C is generally a more recent or upgraded version.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3703\" data-end=\"3982\"\u003e\n\u003cp data-start=\"3706\" data-end=\"3982\"\u003e\u003cstrong data-start=\"3706\" data-end=\"3779\"\u003eIs this bolt critical for maintaining engine performance and sealing?\u003c\/strong\u003e\u003cbr data-start=\"3779\" data-end=\"3782\"\u003e→ Yes. The cylinder head bolt clamps the head to the barrel; incorrect bolt (wrong length or strength) can cause head gasket leaks, warping, or loosening under heat cycles. OEM spec is essential.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3984\" data-end=\"4227\"\u003e\n\u003cp data-start=\"3987\" data-end=\"4227\"\u003e\u003cstrong data-start=\"3987\" data-end=\"4041\"\u003eWill using a non-OEM or cheaper bolt cause issues?\u003c\/strong\u003e\u003cbr data-start=\"4041\" data-end=\"4044\"\u003e→ Potentially yes. Cheaper bolts may use lower tensile spec, incorrect heat treatment, low-quality coating. They can stretch, fail, or corrode, leading to leaks or engine damage.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"4229\" data-end=\"4553\"\u003e\n\u003cp data-start=\"4232\" data-end=\"4553\"\u003e\u003cstrong data-start=\"4232\" data-end=\"4294\"\u003eDo I need any torque spec or re-torque after installation?\u003c\/strong\u003e\u003cbr data-start=\"4294\" data-end=\"4297\"\u003e→ Yes. Use manufacturer prescribed torque settings. After first heat cycle, check bolt torque. In many RE J-Series engines, cylinder head bolts are torque-to-yield or stretch type – check manual. Using OEM bolt, proper torque, and sequence is essential.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ol\u003e","brand":"UNDER THE HOOD","offers":[{"title":"Default Title","offer_id":50424928141607,"sku":null,"price":76.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0878\/7447\/0183\/files\/Hunter_350_cylinder_head_bolt_1570197_C_bolt.jpg?v=1758086949","url":"https:\/\/underthehood.co.in\/products\/royal-enfield-1570197-c-cylinder-head-bolt-m10x181-classic-bullet-350","provider":"UNDER THE HOOD","version":"1.0","type":"link"}