{"product_id":"200x-25h-04c-1-4-pitch-roller-chain-sprocket-c45-steel-12-tooth-10mm-bore-black","title":"200X 25H 04C 1\/4\" Pitch Roller Chain Sprocket C45 Steel 12 Tooth 10mm Bore Black","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003e1\/4\" Pitch Roller Chain Sprocket — Reliable Drive Power for Light-Duty Chain Systems\u003c\/h2\u003e\n\u003cp\u003eWhen a worn or mismatched sprocket causes chain skipping, premature wear, or unexpected downtime on your project, finding a dimensionally accurate replacement becomes critical. Makers, hobbyists, and mechanical engineers working with compact #25 \/ 04C chain drive systems need a sprocket that holds tight tolerances without requiring custom machining. This 200X 25H 04C roller chain sprocket is engineered for that exact use case.\u003c\/p\u003e\n\u003cp\u003eThis sprocket is machined from C45 medium-carbon steel and finished with a black oxide coating for corrosion resistance. It features 12 teeth, a 1\/4\" (6.35 mm) chain pitch conforming to the 04C \/ 25H standard, and a 10 mm bore diameter. The hub is designed to accept a standard set-screw for shaft retention. Overall sprocket outer diameter is typically 25–30 mm depending on tooth geometry, with a hub length of approximately 15–25 mm.\u003c\/p\u003e\n\u003cp\u003eTypical applications include small conveyor systems, go-kart or mini-bike secondary drives, robotics and automation platforms, and DIY power transmission builds requiring a compact 1\/4\" pitch chain sprocket with a 10mm bore. This sprocket is also a direct fit for 25H chain used in motorized bicycle and light industrial equipment projects.\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 #25 \/ 04C \/ 25H roller chain (1\/4\" pitch, 3\/16\" roller width) — verify your chain standard before ordering.\u003c\/div\u003e\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003ch2\u003e✅ Key Features of These 1\/4\" Pitch Roller Chain Sprockets\u003c\/h2\u003e\n\u003cul class=\"hdiy-list\"\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e⚙️\u003c\/span\u003e \u003cstrong\u003eC45 Steel Construction\u003c\/strong\u003e — Machined from medium-carbon C45 steel for solid load-bearing capacity and dimensional stability under cyclic chain loads.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🖤\u003c\/span\u003e \u003cstrong\u003eBlack Oxide Finish\u003c\/strong\u003e — The black oxide surface treatment provides a base layer of corrosion resistance and reduces light reflection in exposed mechanical assemblies.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e \u003cstrong\u003ePrecision 12-Tooth Profile\u003c\/strong\u003e — CNC-machined tooth geometry conforms to 04C \/ 25H chain standards, ensuring consistent chain engagement and reduced wear on both sprocket and chain.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e \u003cstrong\u003e10mm Bore with Set-Screw Hub\u003c\/strong\u003e — The 10 mm bore fits standard metric shafts directly; the set-screw hub allows secure shaft locking without additional keyway machining.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔄\u003c\/span\u003e \u003cstrong\u003eCompact Form Factor\u003c\/strong\u003e — The small outer diameter and narrow hub make this sprocket suitable for space-constrained drive systems where clearance is limited.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🛠️\u003c\/span\u003e \u003cstrong\u003eDrop-In Replacement Fit\u003c\/strong\u003e — Dimensioned to replace OEM 12-tooth 04C sprockets in go-karts, mini conveyors, robotics rigs, and light motorized equipment without modification.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ch2\u003e📐 Technical Specifications — Roller Chain Sprocket\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eChain Standard\u003c\/th\u003e\n\u003ctd\u003e04C \/ 25H \/ #25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eChain Pitch\u003c\/th\u003e\n\u003ctd\u003e1\/4\" (6.35 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of Teeth\u003c\/th\u003e\n\u003ctd\u003e12\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore Diameter\u003c\/th\u003e\n\u003ctd\u003e10 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eC45 Medium-Carbon Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSurface Finish\u003c\/th\u003e\n\u003ctd\u003eBlack Oxide\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\u003eHub Length\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eShaft Retention\u003c\/th\u003e\n\u003ctd\u003eSet-Screw\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eKeyway\u003c\/th\u003e\n\u003ctd\u003eContact us to confirm\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\u003eApplicable Chain Roller Width\u003c\/th\u003e\n\u003ctd\u003e3\/16\" (4.76 mm)\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\u003eWhat chain does this sprocket fit?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThis sprocket is designed for #25 \/ 04C \/ 25H roller chain with a 1\/4\" (6.35 mm) pitch and a 3\/16\" (4.76 mm) roller width. It will not fit #35 or other pitch chains. Always verify your chain's pitch and roller width before ordering.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWill a 10mm bore fit my shaft directly?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eYes — the 10 mm bore is sized for standard metric shafts. The set-screw hub allows you to lock the sprocket onto the shaft without a keyway. If your shaft is imperial (e.g., 3\/8\"), you will need a bore adapter or a different variant.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow strong is C45 steel for chain drive applications?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eC45 medium-carbon steel has a tensile strength of approximately 600–800 MPa in its normalized state, making it well-suited for light-to-medium duty chain drive applications. For high-shock or continuous heavy-load environments, consider a hardened or alloy steel sprocket.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eDoes the black oxide finish prevent rust?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eBlack oxide provides a mild base layer of corrosion resistance and is suitable for indoor or low-humidity environments. For outdoor or wet applications, we recommend applying a light machine oil or grease to the sprocket surface periodically to extend service life.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eIs this compatible with 25H chain used on motorized bicycles?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eYes — 25H chain is dimensionally equivalent to 04C chain (1\/4\" pitch). This 12-tooth sprocket is a common secondary drive sprocket for motorized bicycle builds. Confirm your existing sprocket's tooth count and bore size match before purchasing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do I choose between 12 teeth and other tooth counts?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThe number of teeth on your sprocket determines your drive ratio. A 12-tooth driver paired with a larger driven sprocket produces speed reduction and torque multiplication. Use the formula: Driven RPM = Driver RPM × (Driver Teeth ÷ Driven Teeth). Choose your tooth count based on the speed and torque requirements of your application.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I use this sprocket on a go-kart or mini-bike?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThis sprocket is sized for #25 \/ 04C chain, which is lighter than the #35 or #40 chain typically used on full-size go-karts. It is well-suited for mini-bikes, pocket bikes, and small motorized platforms that use 1\/4\" pitch chain. Verify your chain standard and shaft diameter before ordering.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-cta\"\u003e🛒 Select your bore size and quantity above, then add to cart.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"HomeDIYer","offers":[{"title":"Default Title","offer_id":52423358218514,"sku":"PENGJGJXCD0727x200","price":456.27,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture1of2_a2c4f088-3daa-4c13-9829-958233f1d5b2.jpg?v=1782820504","url":"https:\/\/homediyer.com\/products\/200x-25h-04c-1-4-pitch-roller-chain-sprocket-c45-steel-12-tooth-10mm-bore-black","provider":"HomeDIYer","version":"1.0","type":"link"}