{"product_id":"08b-simplex-roller-chain-sprocket-pilot-bore-12-30t","title":"08B 45#steel sprocket Simplex Roller Chain Pilot Bore 1\/2\" Pitch Sprocket 12-30T","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\n  \u003cdiv class=\"hdiy-overview\"\u003e\n    \u003ch2\u003e08B Simplex Roller Chain Sprocket — Pilot Bore, 1\/2\" Pitch, 12–30T\u003c\/h2\u003e\n    \u003cp\u003eWhen a worn or undersized sprocket is causing chain skip, premature wear, or misalignment in your drive system, finding a dimensionally accurate replacement matters. This 08B simplex roller chain sprocket is designed for engineers, maintenance technicians, and serious DIYers who need a reliable pilot bore sprocket they can machine to their exact shaft size — without compromise.\u003c\/p\u003e\n    \u003cp\u003eEach sprocket is machined from 45# carbon steel, offering a solid balance of hardness and machinability. The pilot bore design ships with a standard through-bore that you finish-bore and key to your shaft specification. Tooth counts range from 12T to 30T, covering a wide spread of drive ratios. The 08B chain standard specifies a 1\/2\" (12.7 mm) pitch, with roller diameter typically 8.51 mm (0.335\") and inner plate width typically 7.75 mm (0.305\").\u003c\/p\u003e\n    \u003cp\u003eTypical applications include conveyor drive systems requiring an 08B simplex sprocket replacement, small industrial gearbox output shafts needing a pilot bore sprocket for custom shaft fitting, and hobbyist or maker projects using standard 08B roller chain for power transmission builds.\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-compat\"\u003e\n    \u003cspan class=\"hdiy-compat-icon\"\u003e🔗\u003c\/span\u003e\n    \u003cstrong\u003eCompatible with:\u003c\/strong\u003e ISO 08B-1 Simplex Roller Chain | 1\/2\" (12.7 mm) Pitch | Roller Diameter ~8.51 mm | Inner Width ~7.75 mm\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-features\"\u003e\n    \u003ch2\u003e✅ Key Features of These 08B Simplex Roller Chain Sprockets\u003c\/h2\u003e\n    \u003cdiv class=\"hdiy-list\"\u003e\n      \u003cdiv\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e⚙️\u003c\/span\u003e\n        \u003cstrong\u003ePilot Bore for Custom Shaft Fitting\u003c\/strong\u003e\n        \u003cp\u003eShips with a standard pilot bore so you can finish-bore, ream, and key the sprocket to your exact shaft diameter — ideal for precision drive builds.\u003c\/p\u003e\n      \u003c\/div\u003e\n      \u003cdiv\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e\n        \u003cstrong\u003e45# Carbon Steel Construction\u003c\/strong\u003e\n        \u003cp\u003eMachined from 45# medium-carbon steel, delivering the hardness needed for sustained chain engagement while remaining machinable for bore finishing operations.\u003c\/p\u003e\n      \u003c\/div\u003e\n      \u003cdiv\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\n        \u003cstrong\u003eISO 08B-1 Simplex Standard\u003c\/strong\u003e\n        \u003cp\u003eTooth profile and pitch dimensions conform to ISO 08B-1 simplex chain standards, ensuring accurate mesh with any compliant 08B roller chain.\u003c\/p\u003e\n      \u003c\/div\u003e\n      \u003cdiv\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🔢\u003c\/span\u003e\n        \u003cstrong\u003eWide Tooth Count Range: 12T – 30T\u003c\/strong\u003e\n        \u003cp\u003eNineteen tooth count options from 12T to 30T let you dial in the drive ratio you need without sourcing a custom sprocket or compromising on geometry.\u003c\/p\u003e\n      \u003c\/div\u003e\n      \u003cdiv\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🛡️\u003c\/span\u003e\n        \u003cstrong\u003eConsistent Dimensional Accuracy\u003c\/strong\u003e\n        \u003cp\u003eEach sprocket is turned and hobbed to consistent tolerances, so chain wrap, pitch circle diameter, and hub dimensions stay within spec across the full tooth range.\u003c\/p\u003e\n      \u003c\/div\u003e\n      \u003cdiv\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🔄\u003c\/span\u003e\n        \u003cstrong\u003eDirect Drop-In Replacement Profile\u003c\/strong\u003e\n        \u003cp\u003eTooth geometry matches standard 08B simplex sprocket profiles, making these a direct replacement for worn sprockets in conveyors, gearboxes, and light industrial drives.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-table-wrap\"\u003e\n    \u003ch2\u003e📐 Technical Specifications — 08B Simplex Roller Chain Sprocket\u003c\/h2\u003e\n    \u003ctable\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003cth\u003eChain Standard\u003c\/th\u003e\n\u003ctd\u003eISO 08B-1 Simplex\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eChain Pitch\u003c\/th\u003e\n\u003ctd\u003e1\/2\" (12.7 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eRoller Diameter\u003c\/th\u003e\n\u003ctd\u003e~8.51 mm (0.335\")\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eInner Plate Width\u003c\/th\u003e\n\u003ctd\u003e~7.75 mm (0.305\")\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eTooth Count (T)\u003c\/th\u003e\n\u003ctd\u003e12T – 30T (see variant options)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eBore Type\u003c\/th\u003e\n\u003ctd\u003ePilot Bore (finish to shaft size)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003e45# Carbon Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eFinish\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eHub Diameter\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eHub Length\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eOverall Width\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003ePitch Circle Diameter\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\n  \u003cdiv class=\"hdiy-faq\"\u003e\n    \u003ch2\u003e❓ Frequently Asked Questions\u003c\/h2\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eHow do I choose the right tooth count for my drive?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThe tooth count determines your drive ratio. Divide the driven sprocket teeth by the driver sprocket teeth to get the ratio. For example, a 12T driver paired with a 24T driven sprocket gives a 2:1 reduction. Select the tooth count that achieves your target output speed or torque from the Size dropdown above.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat chain does this sprocket fit?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThis sprocket is designed for ISO 08B-1 simplex roller chain with a 1\/2\" (12.7 mm) pitch. It is not compatible with duplex (08B-2) or triplex (08B-3) chain, nor with ANSI #40 chain, which shares the same pitch but has different roller and plate dimensions.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat is a pilot bore sprocket and how do I finish it?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eA pilot bore sprocket ships with a small through-bore (the \"pilot\") that is smaller than your shaft. You take it to a machine shop or use a lathe to bore it out to your exact shaft diameter, then cut a keyway if required. This gives you a precise, custom fit that a fixed-bore sprocket cannot provide.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eIs 45# carbon steel strong enough for my application?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003e45# carbon steel (equivalent to C45 \/ SAE 1045) has a tensile strength typically in the range of 600–800 MPa and is well-suited for light to medium-duty industrial drives, conveyor systems, and power transmission applications. For heavy shock loads or highly abrasive environments, consider a hardened or alloy steel sprocket.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWill this sprocket rust or corrode?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eCarbon steel sprockets are susceptible to surface oxidation in humid or wet environments. For indoor or dry applications, standard lubrication is sufficient. For outdoor or washdown environments, consider applying a corrosion-inhibiting lubricant regularly, or contact us to discuss alternative material options.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eCan I use this sprocket with a chain tensioner or idler?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. These sprockets are compatible with standard 08B chain tensioners and idler arrangements. Ensure the idler sprocket tooth count and bore are matched to your chain and shaft, and that chain wrap angle on the driver sprocket remains above 120° for reliable power transmission.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eHow do I confirm the pitch circle diameter before ordering?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThe pitch circle diameter (PCD) for a roller chain sprocket is calculated as: PCD = Pitch ÷ sin(180° ÷ T), where Pitch = 12.7 mm and T = number of teeth. For example, a 20T sprocket gives PCD = 12.7 ÷ sin(9°) ≈ 81.2 mm. If you need the exact hub and OD dimensions for your specific tooth count, contact us to confirm before ordering.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-cta\"\u003e\n    🛒 Select your Size (tooth count) above, then add to cart.\n  \u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"HomeDIYer","offers":[{"title":"08B - 12T \/ 1 pcs","offer_id":52423409402130,"sku":"GYWYPSHXJZC2829x1","price":15.22,"currency_code":"USD","in_stock":true},{"title":"08B - 13T \/ 1 pcs","offer_id":52423409434898,"sku":"GYWYPSHXJZC2830x1","price":19.84,"currency_code":"USD","in_stock":true},{"title":"08B - 14T \/ 1 pcs","offer_id":52423409467666,"sku":"GYWYPSHXJZC2831x1","price":22.37,"currency_code":"USD","in_stock":true},{"title":"08B - 15T \/ 1 pcs","offer_id":52423409500434,"sku":"GYWYPSHXJZC2832x1","price":24.6,"currency_code":"USD","in_stock":true},{"title":"08B - 16T \/ 1 pcs","offer_id":52423409533202,"sku":"GYWYPSHXJZC2833x1","price":26.37,"currency_code":"USD","in_stock":true},{"title":"08B - 17T \/ 1 pcs","offer_id":52423409565970,"sku":"GYWYPSHXJZC2834x1","price":28.95,"currency_code":"USD","in_stock":true},{"title":"08B - 18T \/ 1 pcs","offer_id":52423409598738,"sku":"GYWYPSHXJZC2835x1","price":32.76,"currency_code":"USD","in_stock":true},{"title":"08B - 19T \/ 1 pcs","offer_id":52423409631506,"sku":"GYWYPSHXJZC2836x1","price":37.6,"currency_code":"USD","in_stock":true},{"title":"08B - 20T \/ 1 pcs","offer_id":52423409664274,"sku":"GYWYPSHXJZC2837x1","price":42.28,"currency_code":"USD","in_stock":true},{"title":"08B - 21T \/ 1 pcs","offer_id":52423409697042,"sku":"GYWYPSHXJZC2849x1","price":46.91,"currency_code":"USD","in_stock":true},{"title":"08B - 22T \/ 1 pcs","offer_id":52423409729810,"sku":"GYWYPSHXJZC2850x1","price":50.44,"currency_code":"USD","in_stock":true},{"title":"08B - 23T \/ 1 pcs","offer_id":52423409762578,"sku":"GYWYPSHXJZC2851x1","price":52.16,"currency_code":"USD","in_stock":true},{"title":"08B - 24T \/ 1 pcs","offer_id":52423409795346,"sku":"GYWYPSHXJZC2852x1","price":53.71,"currency_code":"USD","in_stock":true},{"title":"08B - 25T \/ 1 pcs","offer_id":52423409828114,"sku":"GYWYPSHXJZC2853x1","price":58.87,"currency_code":"USD","in_stock":true},{"title":"08B - 26T \/ 1 pcs","offer_id":52423409860882,"sku":"GYWYPSHXJZC2854x1","price":60.51,"currency_code":"USD","in_stock":true},{"title":"08B - 27T \/ 1 pcs","offer_id":52423409893650,"sku":"GYWYPSHXJZC2855x1","price":62.27,"currency_code":"USD","in_stock":true},{"title":"08B - 28T \/ 1 pcs","offer_id":52423409926418,"sku":"GYWYPSHXJZC2856x1","price":64.45,"currency_code":"USD","in_stock":true},{"title":"08B - 29T \/ 1 pcs","offer_id":52423409959186,"sku":"GYWYPSHXJZC2857x1","price":77.23,"currency_code":"USD","in_stock":true},{"title":"08B - 30T \/ 1 pcs","offer_id":52423409991954,"sku":"GYWYPSHXJZC2858x1","price":79.76,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture3of6_5696eea9-e524-4ea9-88af-7c6606ffdae1.jpg?v=1782831464","url":"https:\/\/homediyer.com\/products\/08b-simplex-roller-chain-sprocket-pilot-bore-12-30t","provider":"HomeDIYer","version":"1.0","type":"link"}