{"product_id":"05-mod-brass-spur-gear-45-teeth-bore-4-10mm-cnc-pinion-gear","title":"0.5 Mod Brass Pinion Spur Gear 45 Teeth Bore 4\/5\/6\/8\/10mm CNC Transmission Gear","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003e0.5 Mod Brass Spur Gear 45T — Reliable CNC Pinion for Precision Drive Systems\u003c\/h2\u003e\n\u003cp\u003eWhen a loose-fitting or undersized pinion causes slippage, noise, or premature wear in your drive train, the root cause is almost always a mismatch between bore diameter and shaft size. Hobbyists building RC vehicles, engineers prototyping CNC actuators, and makers assembling small automation rigs all face the same challenge: finding a compact spur gear that fits the shaft exactly and holds up under continuous load.\u003c\/p\u003e\n\u003cp\u003eThis 0.5 Module brass spur gear features 45 teeth and is available with bore diameters of 4 mm (~0.157 in), 5 mm (~0.197 in), 6 mm (~0.236 in), 8 mm (~0.315 in), and 10 mm (~0.394 in). The gear body is machined from solid brass, offering a balance of machinability, corrosion resistance, and low-friction meshing. Outer diameter is approximately 23 mm (~0.906 in) based on the 0.5 mod × 45T formula (OD = (T+2) × module).\u003c\/p\u003e\n\u003cp\u003eTypical use cases include: \u003cstrong\u003eCNC router axis drives\u003c\/strong\u003e requiring quiet, low-backlash transmission; \u003cstrong\u003erobotics joint actuators\u003c\/strong\u003e where a compact 45-tooth reduction stage is needed; and \u003cstrong\u003eRC model gear trains\u003c\/strong\u003e where a brass pinion meshes with a nylon or steel rack for smooth, durable operation.\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\u003eCompatibility:\u003c\/strong\u003e Designed for 0.5 Module gear systems. Meshes with any 0.5 Mod rack, pinion, or mating gear. Verify bore diameter matches your motor or shaft before ordering.\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003ch2\u003e✅ Key Features of These 0.5 Mod Brass Spur Gears\u003c\/h2\u003e\n\u003cul class=\"hdiy-list\"\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e\u003cstrong\u003eSolid Brass Construction\u003c\/strong\u003e\u003cbr\u003eMachined from brass for inherent corrosion resistance, low friction against mating gears, and easy re-machining if custom bore sizing is needed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\u003cstrong\u003e45-Tooth Profile, 0.5 Module\u003c\/strong\u003e\u003cbr\u003eStandard 0.5 Mod tooth geometry ensures accurate meshing with any compatible 0.5 Mod rack or gear. OD ≈ 23 mm (0.906 in); face width typically 5–8 mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🎯\u003c\/span\u003e\u003cstrong\u003e5 Bore Sizes Available\u003c\/strong\u003e\u003cbr\u003eChoose from 4 \/ 5 \/ 6 \/ 8 \/ 10 mm bore to match your motor shaft or drive shaft directly — no adapter sleeve required in most applications.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e⚡\u003c\/span\u003e\u003cstrong\u003eBulk Packing Options\u003c\/strong\u003e\u003cbr\u003eAvailable in 1, 2, 5, or 10-piece packs. Order spares for prototyping or stock multiple bore sizes for different builds in a single transaction.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔄\u003c\/span\u003e\u003cstrong\u003eLow-Backlash Meshing\u003c\/strong\u003e\u003cbr\u003ePrecision-cut tooth profile minimizes backlash in closed-loop positioning systems, making these gears suitable for light-duty CNC and servo-driven stages.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🛠️\u003c\/span\u003e\u003cstrong\u003eVersatile Application Range\u003c\/strong\u003e\u003cbr\u003eSuitable for RC vehicles, desktop CNC machines, 3D printer extruder drives, small robotic arms, and educational mechanism kits requiring a compact 45T reduction stage.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ch2\u003e📐 Technical Specifications — 0.5 Mod Brass Spur Gear\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eModule\u003c\/th\u003e\n\u003ctd\u003e0.5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of Teeth\u003c\/th\u003e\n\u003ctd\u003e45T\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOuter Diameter\u003c\/th\u003e\n\u003ctd\u003e≈ 23 mm (0.906 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore Diameter\u003c\/th\u003e\n\u003ctd\u003e4 \/ 5 \/ 6 \/ 8 \/ 10 mm (see variant options)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFace Width\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eBrass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePressure Angle\u003c\/th\u003e\n\u003ctd\u003e20°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTooth Profile\u003c\/th\u003e\n\u003ctd\u003eInvolute\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFinish\u003c\/th\u003e\n\u003ctd\u003eNatural brass (uncoated)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePacking Quantity\u003c\/th\u003e\n\u003ctd\u003e1 \/ 2 \/ 5 \/ 10 PCS (see 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\u003cdetails\u003e\n\u003csummary\u003eHow do I choose the right bore size?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eMeasure your motor or drive shaft diameter with a caliper. Select the bore size that matches exactly — 4, 5, 6, 8, or 10 mm. A bore that is too large will cause runout and slippage; a bore that is too small cannot be pressed on without machining. If your shaft is an imperial size (e.g. 1\/4 in = 6.35 mm), choose the next available metric bore and ream or sleeve to fit.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat is the outer diameter of this 45-tooth 0.5 Mod gear?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eFor a 0.5 Module gear with 45 teeth, the outer (tip) diameter is calculated as OD = (T + 2) × Module = (45 + 2) × 0.5 = 23.5 mm. In practice, finished OD is approximately 23–23.5 mm (~0.906–0.925 in) depending on machining tolerance.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eIs brass strong enough for my application?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eBrass spur gears are well-suited for light-to-medium duty applications such as RC models, desktop CNC drives, and small robotic joints. Brass offers good machinability and low friction against steel or nylon mating gears. For heavy-load or high-speed industrial drives, consider steel gears instead. If in doubt, contact us with your torque and RPM requirements.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWill this gear resist corrosion?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eBrass has natural corrosion resistance in most indoor and light-outdoor environments. It does not rust like steel. However, in highly humid, salt-spray, or chemically aggressive environments, consider applying a light machine oil or grease to the tooth surfaces for added protection.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat mating gears or racks are compatible?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThis gear meshes with any 0.5 Module gear or rack with a matching 20° pressure angle — regardless of material (brass, steel, nylon, or acetal). Ensure the mating component is also 0.5 Mod; mixing modules will result in incorrect meshing and rapid wear.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I order multiple bore sizes in one order?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. Each bore size is a separate variant. Add the desired bore size and quantity combination to your cart, then repeat for additional bore sizes. All items will be consolidated into a single order.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat is the difference between 1 PCS, 2 PCS, 5 PCS, and 10 PCS packs?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThe packing quantity refers to the number of identical gears (same bore size) included in one purchase. Multi-piece packs offer a lower per-unit cost and are useful for prototyping with spares, building symmetric gear trains, or stocking your workshop.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-cta\"\u003e\n🛒 Select your bore size and packing quantity above, then add to cart.\n\u003c\/div\u003e\n\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How do I choose the right bore size?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Measure your motor or drive shaft diameter with a caliper. Select the bore size that matches exactly — 4, 5, 6, 8, or 10 mm. A bore that is too large will cause runout and slippage; a bore that is too small cannot be pressed on without machining.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the outer diameter of this 45-tooth 0.5 Mod gear?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"OD = (45 + 2) × 0.5 = 23.5 mm. Finished OD is approximately 23–23.5 mm (~0.906–0.925 in) depending on machining tolerance.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is brass strong enough for my application?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Brass spur gears are well-suited for light-to-medium duty applications such as RC models, desktop CNC drives, and small robotic joints. For heavy-load or high-speed industrial drives, consider steel gears instead.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will this gear resist corrosion?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Brass has natural corrosion resistance in most indoor and light-outdoor environments. It does not rust like steel. Apply a light machine oil or grease in humid or chemically aggressive environments.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What mating gears or racks are compatible?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"This gear meshes with any 0.5 Module gear or rack with a matching 20° pressure angle. Ensure the mating component is also 0.5 Mod; mixing modules will result in incorrect meshing and rapid wear.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I order multiple bore sizes in one order?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. Each bore size is a separate variant. Add the desired bore size and quantity combination to your cart, then repeat for additional bore sizes.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the difference between 1 PCS, 2 PCS, 5 PCS, and 10 PCS packs?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The packing quantity refers to the number of identical gears included in one purchase. Multi-piece packs offer a lower per-unit cost and are useful for prototyping with spares or stocking your workshop.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"HomeDIYer","offers":[{"title":"0.5 Mod 45T 【Bore 4mm】 \/ 1 PCS","offer_id":52442811138322,"sku":"AdaahGFCD04458x1","price":11.15,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 5mm】 \/ 1 PCS","offer_id":52442811171090,"sku":"AdaahGFCD04459x1","price":11.15,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 6mm】 \/ 1 PCS","offer_id":52442811203858,"sku":"AdaahGFCD04460x1","price":11.15,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 8mm】 \/ 1 PCS","offer_id":52442811236626,"sku":"AdaahGFCD04461x1","price":11.15,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 10mm】 \/ 1 PCS","offer_id":52442811269394,"sku":"AdaahGFCD04462x1","price":11.15,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 4mm】 \/ 2 PCS","offer_id":52442811302162,"sku":"AdaahGFCD04458x2","price":17.14,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 5mm】 \/ 2 PCS","offer_id":52442811334930,"sku":"AdaahGFCD04459x2","price":17.05,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 6mm】 \/ 2 PCS","offer_id":52442811367698,"sku":"AdaahGFCD04460x2","price":17.05,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 8mm】 \/ 2 PCS","offer_id":52442811400466,"sku":"AdaahGFCD04461x2","price":16.89,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 10mm】 \/ 2 PCS","offer_id":52442811433234,"sku":"AdaahGFCD04462x2","price":16.76,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 4mm】 \/ 5 PCS","offer_id":52442811466002,"sku":"AdaahGFCD04458x5","price":37.93,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 5mm】 \/ 5 PCS","offer_id":52442811498770,"sku":"AdaahGFCD04459x5","price":37.88,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 6mm】 \/ 5 PCS","offer_id":52442811531538,"sku":"AdaahGFCD04460x5","price":37.74,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 8mm】 \/ 5 PCS","offer_id":52442811564306,"sku":"AdaahGFCD04461x5","price":37.39,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 10mm】 \/ 5 PCS","offer_id":52442811597074,"sku":"AdaahGFCD04462x5","price":36.98,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 4mm】 \/ 10 PCS","offer_id":52442811629842,"sku":"AdaahGFCD04458x10","price":74.79,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 5mm】 \/ 10 PCS","offer_id":52442811662610,"sku":"AdaahGFCD04459x10","price":74.6,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 6mm】 \/ 10 PCS","offer_id":52442811695378,"sku":"AdaahGFCD04460x10","price":74.32,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 8mm】 \/ 10 PCS","offer_id":52442811728146,"sku":"AdaahGFCD04461x10","price":73.7,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 45T 【Bore 10mm】 \/ 10 PCS","offer_id":52442811760914,"sku":"AdaahGFCD04462x10","price":72.88,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture5of12_29b7d63d-04b7-4755-a4d2-58d42ca92a09.jpg?v=1783602899","url":"https:\/\/homediyer.com\/products\/05-mod-brass-spur-gear-45-teeth-bore-4-10mm-cnc-pinion-gear","provider":"HomeDIYer","version":"1.0","type":"link"}