{"product_id":"40-roller-chain-drive-sprocket-9t-40t-pitch-1-2-12-7mm-for-40-08b-chain","title":"#40 Roller Chain Drive Sprocket 9T-40T Pitch 1\/2\" 12.7mm For #40 08B Chain","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003e#40 Roller Chain Drive Sprocket — Precision-Cut 9T to 40T for #40 \u0026amp; 08B Chain\u003c\/h2\u003e\n\u003cp\u003eWhen a worn or undersized sprocket causes chain skip, premature wear, or misalignment in your drivetrain build, the fix starts with a correctly matched sprocket. Whether you're a maker building a go-kart, a DIYer assembling a conveyor, or a hobbyist upgrading a mini-bike, these #40 roller chain drive sprockets give you the exact tooth count you need without compromise.\u003c\/p\u003e\n\u003cp\u003eEach sprocket is machined from carbon steel with a hardened tooth profile, sized to the ANSI #40 \/ ISO 08B standard pitch of 1\/2\" (12.7 mm). Tooth counts span 9T through 40T, covering a wide range of gear ratios. Bore diameter varies by tooth count — see variant options for your specific selection.\u003c\/p\u003e\n\u003cp\u003eTypical applications include go-kart and mini-bike chain drives, DIY conveyor and indexing systems, electric motor reduction stages, and small-engine power transmission projects where a reliable #40 chain sprocket replacement or upgrade is required.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-compat\"\u003e\n\u003cspan class=\"hdiy-compat-icon\"\u003e🔗\u003c\/span\u003e \u003cstrong\u003eCompatible with:\u003c\/strong\u003e ANSI #40 roller chain \u0026amp; ISO 08B roller chain — Pitch: 1\/2\" (12.7 mm) | Roller Width: 5\/16\" (7.94 mm) | Roller Diameter: 0.306\" (7.77 mm)\u003c\/div\u003e\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003ch2\u003e✅ Key Features of These #40 Roller Chain Drive Sprockets\u003c\/h2\u003e\n\u003cul class=\"hdiy-list\"\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e⚙️\u003c\/span\u003e\u003cstrong\u003eWide Tooth Count Range (9T–40T):\u003c\/strong\u003e Choose from 32 tooth count variants to dial in your exact drive ratio for go-karts, conveyors, mini-bikes, and custom power transmission builds.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\u003cstrong\u003eANSI #40 \/ ISO 08B Standard Pitch:\u003c\/strong\u003e Machined to the 1\/2\" (12.7 mm) pitch standard, ensuring drop-in compatibility with any #40 or 08B roller chain without shimming or modification.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e\u003cstrong\u003eHardened Steel Tooth Profile:\u003c\/strong\u003e Teeth are hardened for wear resistance, extending service life under continuous load cycling and reducing chain elongation over time.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🎯\u003c\/span\u003e\u003cstrong\u003ePrecision-Cut Hub and Bore:\u003c\/strong\u003e Each sprocket is turned and bored to consistent tolerances, minimizing runout and vibration for smooth, quiet chain engagement at operating speed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔄\u003c\/span\u003e\u003cstrong\u003eBroad Application Compatibility:\u003c\/strong\u003e Suitable for electric motor drives, small-engine transmissions, indexing tables, and any DIY drivetrain where #40 chain is the standard.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📦\u003c\/span\u003e\u003cstrong\u003eSingle-Piece Solid Construction:\u003c\/strong\u003e One-piece solid sprocket body with no pressed inserts or laminated plates — built to handle torque loads without delamination or hub separation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ch2\u003e📐 Technical Specifications — #40 Roller Chain Sprocket\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eChain Standard\u003c\/th\u003e\n\u003ctd\u003eANSI #40 \/ ISO 08B\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePitch\u003c\/th\u003e\n\u003ctd\u003e1\/2\" (12.7 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eRoller Width\u003c\/th\u003e\n\u003ctd\u003e5\/16\" (7.94 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eRoller Diameter\u003c\/th\u003e\n\u003ctd\u003e0.306\" (7.77 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTooth Count\u003c\/th\u003e\n\u003ctd\u003e9T – 40T (select variant)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eCarbon Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTooth Finish\u003c\/th\u003e\n\u003ctd\u003eHardened\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHub Style\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore Diameter\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOuter Diameter\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSurface Treatment\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-faq\"\u003e\n\u003ch2\u003e❓ Frequently Asked Questions\u003c\/h2\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do I choose the right tooth count for my application?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eTooth count determines your drive ratio. Divide the driven sprocket teeth by the drive sprocket teeth to get the reduction ratio. For example, a 9T drive sprocket paired with a 36T driven sprocket gives a 4:1 reduction. Lower tooth counts on the drive side increase torque; higher counts increase speed. Match your motor RPM and desired output RPM to select the correct pairing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWill this sprocket fit both ANSI #40 and ISO 08B chain?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eYes. ANSI #40 and ISO 08B share the same 1\/2\" (12.7 mm) pitch and are dimensionally interchangeable in most applications. These sprockets are machined to that shared pitch standard and will engage correctly with either chain type.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat bore diameter does each sprocket have?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eBore diameter varies by tooth count and hub style. Please refer to the variant detail page or contact us to confirm the bore size for your selected tooth count before ordering. Many variants are available with a pilot bore that can be finish-bored to your shaft diameter.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow strong are these sprockets under continuous load?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThe sprockets are machined from carbon steel with hardened teeth, providing solid fatigue resistance under cyclic loading. For exact tensile and shear ratings, refer to the ANSI #40 chain load table and match the sprocket's tooth count to your chain's working load limit. Contact us if you need application-specific load confirmation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eAre these sprockets corrosion-resistant for outdoor or wet environments?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThe base material is carbon steel, which is not inherently corrosion-resistant. For outdoor or high-humidity environments, we recommend applying a chain lubricant or anti-rust coating regularly. If your application requires stainless steel or zinc-plated sprockets, please contact us to discuss available options.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I use these sprockets on a go-kart or mini-bike?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eYes — #40 chain drive is one of the most common standards for go-karts and mini-bikes. Select the tooth count that matches your existing rear axle sprocket or engine output sprocket. Confirm the bore diameter matches your axle or crankshaft diameter before ordering.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat is the difference between a 9T and a 40T sprocket in practice?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eA 9T sprocket is a small-diameter drive sprocket typically used on the motor or engine output shaft to achieve high reduction ratios. A 40T sprocket is a large-diameter driven sprocket used on the axle or output shaft. Using a 9T drive with a 40T driven sprocket gives approximately a 4.4:1 reduction, multiplying torque while reducing speed.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-cta\"\u003e🛒 Select your \u003cstrong\u003eSprocket Type\u003c\/strong\u003e above, then add to cart.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"HomeDIYer","offers":[{"title":"#40-9T","offer_id":52423300743442,"sku":"GF2588A-0","price":8.68,"currency_code":"USD","in_stock":true},{"title":"#40-10T","offer_id":52423300776210,"sku":"GF2588A-1","price":9.6,"currency_code":"USD","in_stock":true},{"title":"#40-11T","offer_id":52423300808978,"sku":"GF2588A-2","price":10.53,"currency_code":"USD","in_stock":true},{"title":"#40-12T","offer_id":52423300841746,"sku":"GF2588A-3","price":11.45,"currency_code":"USD","in_stock":true},{"title":"#40-13T","offer_id":52423300874514,"sku":"GF2588A-4","price":12.55,"currency_code":"USD","in_stock":true},{"title":"#40-14T","offer_id":52423300907282,"sku":"GF2588A-5","price":14.04,"currency_code":"USD","in_stock":true},{"title":"#40-15T","offer_id":52423300940050,"sku":"GF2588A-6","price":17.0,"currency_code":"USD","in_stock":true},{"title":"#40-16T","offer_id":52423300972818,"sku":"GF2588A-7","price":19.58,"currency_code":"USD","in_stock":true},{"title":"#40-17T","offer_id":52423301005586,"sku":"GF2588A-8","price":21.62,"currency_code":"USD","in_stock":true},{"title":"#40-18T","offer_id":52423301038354,"sku":"GF2588A-9","price":23.85,"currency_code":"USD","in_stock":true},{"title":"#40-19T","offer_id":52423301071122,"sku":"GF2588A-10","price":26.42,"currency_code":"USD","in_stock":true},{"title":"#40-20T","offer_id":52423301103890,"sku":"GF2588A-11","price":29.4,"currency_code":"USD","in_stock":true},{"title":"#40-21T","offer_id":52423301136658,"sku":"GF2588A-12","price":29.95,"currency_code":"USD","in_stock":true},{"title":"#40-22T","offer_id":52423301169426,"sku":"GF2588A-13","price":30.89,"currency_code":"USD","in_stock":true},{"title":"#40-23T","offer_id":52423301202194,"sku":"GF2588A-14","price":31.97,"currency_code":"USD","in_stock":true},{"title":"#40-24T","offer_id":52423301234962,"sku":"GF2588A-15","price":33.09,"currency_code":"USD","in_stock":true},{"title":"#40-25T","offer_id":52423301267730,"sku":"GF2588A-16","price":34.75,"currency_code":"USD","in_stock":true},{"title":"#40-26T","offer_id":52423301300498,"sku":"GF2588A-17","price":44.74,"currency_code":"USD","in_stock":true},{"title":"#40-27T","offer_id":52423301333266,"sku":"GF2588A-18","price":47.53,"currency_code":"USD","in_stock":true},{"title":"#40-28T","offer_id":52423301366034,"sku":"GF2588A-19","price":50.47,"currency_code":"USD","in_stock":true},{"title":"#40-29T","offer_id":52423301398802,"sku":"GF2588A-20","price":54.55,"currency_code":"USD","in_stock":true},{"title":"#40-30T","offer_id":52423301431570,"sku":"GF2588A-21","price":58.43,"currency_code":"USD","in_stock":true},{"title":"#40-31T","offer_id":52423301464338,"sku":"GF2588A-22","price":61.95,"currency_code":"USD","in_stock":true},{"title":"#40-32T","offer_id":52423301497106,"sku":"GF2588A-23","price":63.05,"currency_code":"USD","in_stock":true},{"title":"#40-33T","offer_id":52423301529874,"sku":"GF2588A-24","price":68.04,"currency_code":"USD","in_stock":true},{"title":"#40-34T","offer_id":52423301562642,"sku":"GF2588A-25","price":69.71,"currency_code":"USD","in_stock":true},{"title":"#40-35T","offer_id":52423301595410,"sku":"GF2588A-26","price":75.28,"currency_code":"USD","in_stock":true},{"title":"#40-36T","offer_id":52423301628178,"sku":"GF2588A-27","price":79.53,"currency_code":"USD","in_stock":true},{"title":"#40-37T","offer_id":52423301660946,"sku":"GF2588A-28","price":85.8,"currency_code":"USD","in_stock":true},{"title":"#40-38T","offer_id":52423301693714,"sku":"GF2588A-29","price":89.5,"currency_code":"USD","in_stock":true},{"title":"#40-39T","offer_id":52423301726482,"sku":"GF2588A-30","price":90.79,"currency_code":"USD","in_stock":true},{"title":"#40-40T","offer_id":52423301759250,"sku":"GF2588A-31","price":97.27,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture1of5_564fe102-2116-49a4-aba1-fcbfd4ca5f7b.jpg?v=1782732520","url":"https:\/\/homediyer.com\/products\/40-roller-chain-drive-sprocket-9t-40t-pitch-1-2-12-7mm-for-40-08b-chain","provider":"HomeDIYer","version":"1.0","type":"link"}