{"product_id":"2-5mod-spur-gear-45-steel-25mm-10t-47t-motor-pinion-transmission","title":"2.5Mod 10T-47T Spur Gear 45#Steel Thickness 25mm Motor Pinion Transmission Gear","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\n  \u003cdiv class=\"hdiy-overview\"\u003e\n    \u003ch2\u003e2.5 Module Spur Gear in 45# Steel — Reliable Pinion \u0026amp; Transmission Drive for Makers and Engineers\u003c\/h2\u003e\n    \u003cp\u003eWhen a stripped or undersized gear brings your CNC router, robotic arm, or custom drive train to a halt, you need a replacement that holds tolerance under load. These 2.5 module spur gears are engineered for hobbyists, prototype builders, and small-batch manufacturers who demand consistent mesh accuracy without sourcing from a full industrial catalog.\u003c\/p\u003e\n    \u003cp\u003eEach gear is machined from 45# medium-carbon steel — a material known for its balanced hardness and machinability — and features a 25 mm (approximately 0.984 in) face width. The tooth count spans from 10 T to 47 T, giving you a pitch circle diameter range of roughly 25 mm (0.984 in) for the 10-tooth variant up to approximately 117.5 mm (4.626 in) for the 47-tooth variant. Bore diameter varies by tooth count; confirm your shaft size against the variant listing before ordering.\u003c\/p\u003e\n    \u003cp\u003eTypical use cases include motor-to-gearbox pinion stages in DIY CNC machines, speed-reduction transmission assemblies in robotics and automation rigs, and replacement drive gears in 3D printer extruder or axis systems requiring a 2.5 mod standard pitch.\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 to mesh with any standard Module 2.5 (Mod 2.5) spur or helical gear of matching pressure angle (typically 20°). Verify bore diameter and keyway requirements against your shaft spec before ordering.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-features\"\u003e\n    \u003ch2\u003e✅ Key Features of These 2.5 Module Spur Gears\u003c\/h2\u003e\n    \u003cul class=\"hdiy-list\"\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e\n        \u003cstrong\u003e45# Medium-Carbon Steel Construction\u003c\/strong\u003e — Offers a solid balance of tensile strength and machinability, suitable for moderate-to-high torque transmission applications.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\n        \u003cstrong\u003e25 mm Face Width (≈ 0.984 in)\u003c\/strong\u003e — Wider face distributes load across more tooth surface area, reducing wear rate compared to thinner gears under equivalent torque.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🔢\u003c\/span\u003e\n        \u003cstrong\u003e10 T to 47 T Tooth Range\u003c\/strong\u003e — Broad selection in a single product listing lets you dial in your exact gear ratio without sourcing from multiple suppliers.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🎯\u003c\/span\u003e\n        \u003cstrong\u003eStandard Mod 2.5 Pitch\u003c\/strong\u003e — Conforms to the ISO\/DIN module system, ensuring predictable mesh with any other Mod 2.5 gear in your drivetrain.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e⚡\u003c\/span\u003e\n        \u003cstrong\u003eMotor Pinion Ready\u003c\/strong\u003e — Compact small-tooth variants (10 T–15 T) are sized for direct mounting on common motor shafts in robotics and automation builds.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🔄\u003c\/span\u003e\n        \u003cstrong\u003eWide Ratio Coverage\u003c\/strong\u003e — Pair any two tooth counts from this range to achieve gear ratios from approximately 1.06:1 up to 4.7:1 within a single module family.\n      \u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-table-wrap\"\u003e\n    \u003ch2\u003e📐 Technical Specifications — 2.5 Module Spur Gear\u003c\/h2\u003e\n    \u003ctable\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003cth\u003eModule\u003c\/th\u003e\n\u003ctd\u003e2.5\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 Count Range\u003c\/th\u003e\n\u003ctd\u003e10 T – 47 T (select variant)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eFace Width (Thickness)\u003c\/th\u003e\n\u003ctd\u003e25 mm (≈ 0.984 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003ePitch Circle Diameter\u003c\/th\u003e\n\u003ctd\u003e25 mm – 117.5 mm (varies by tooth count)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003e45# Medium-Carbon Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eSurface Finish\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\u003eKeyway\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\u003eOverall Diameter (OD)\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\u003eGear Standard\u003c\/th\u003e\n\u003ctd\u003eISO\/DIN Module System\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 application?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eDetermine your required gear ratio first: divide the driver tooth count by the driven tooth count. For example, pairing a 10 T pinion with a 30 T gear gives a 3:1 reduction. Select the tooth count that achieves your target ratio while keeping the center distance compatible with your housing or frame design. Center distance = (T1 + T2) × Module \/ 2.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat is the bore diameter for each tooth count variant?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eBore diameter varies by tooth count and is listed in the individual variant details. Please check the variant specification or contact us to confirm the bore size before ordering, especially if you need a specific shaft fit.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eCan these gears handle high-torque or continuous-duty applications?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003e45# steel provides solid load-bearing capacity for moderate-to-high torque in intermittent or continuous-duty cycles. For very high-speed or heavy industrial loads, consider whether a heat-treated or case-hardened variant is more appropriate for your duty cycle. These gears are well-suited for robotics, CNC, and maker-grade machinery.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eAre these gears corrosion-resistant?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003e45# carbon steel has moderate corrosion resistance. For environments with moisture, coolant exposure, or outdoor use, we recommend applying a light machine oil or grease coating during installation and periodically during service. If corrosion resistance is a primary requirement, consider stainless steel or plastic gear alternatives.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWill this gear mesh with my existing Mod 2.5 gears from another supplier?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes — as long as your existing gears conform to the standard Module 2.5 pitch with a 20° pressure angle, these gears will mesh correctly. Module and pressure angle must match between mating gears; tooth count only affects ratio and center distance.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat is the difference between a pinion gear and a spur gear in this context?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eA pinion is simply the smaller of two meshing spur gears — typically the driver gear mounted on a motor shaft. In this listing, the lower tooth-count variants (10 T–15 T) are commonly used as pinion gears, while larger tooth-count variants serve as the driven gear in a reduction stage. Both are standard spur gears with straight, parallel teeth.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eDo I need a keyway or set screw to mount this gear on a shaft?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eMounting method (keyway, set screw, or interference fit) depends on the specific variant. Please check the variant detail page or contact us to confirm the hub configuration for your selected tooth count before finalizing your design.\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 tooth count (Model) 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 tooth count for my application?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Determine your required gear ratio first: divide the driver tooth count by the driven tooth count. For example, pairing a 10T pinion with a 30T gear gives a 3:1 reduction. Center distance = (T1 + T2) × Module \/ 2.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the bore diameter for each tooth count variant?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Bore diameter varies by tooth count and is listed in the individual variant details. Please check the variant specification or contact us to confirm before ordering.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can these gears handle high-torque or continuous-duty applications?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"45# steel provides solid load-bearing capacity for moderate-to-high torque in intermittent or continuous-duty cycles. These gears are well-suited for robotics, CNC, and maker-grade machinery.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Are these gears corrosion-resistant?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"45# carbon steel has moderate corrosion resistance. Apply a light machine oil or grease coating during installation and periodically during service for moisture or coolant environments.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will this gear mesh with my existing Mod 2.5 gears from another supplier?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — as long as your existing gears conform to Module 2.5 pitch with a 20° pressure angle, these gears will mesh correctly.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the difference between a pinion gear and a spur gear in this context?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"A pinion is the smaller of two meshing spur gears, typically the driver gear on a motor shaft. Lower tooth-count variants (10T–15T) are commonly used as pinion gears.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Do I need a keyway or set screw to mount this gear on a shaft?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Mounting method depends on the specific variant. Please check the variant detail page or contact us to confirm the hub configuration for your selected tooth count.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"HomeDIYer","offers":[{"title":"2.5Mod 10Teeth","offer_id":52442836664594,"sku":"GLFBLFFGLBZSJ058105x1","price":10.3,"currency_code":"USD","in_stock":true},{"title":"2.5Mod 11Teeth","offer_id":52442836697362,"sku":"GLFBLFFGLBZSJ058106x1","price":14.55,"currency_code":"USD","in_stock":true},{"title":"2.5Mod 12Teeth","offer_id":52442836730130,"sku":"GLFBLFFGLBZSJ058107x1","price":17.22,"currency_code":"USD","in_stock":true},{"title":"2.5Mod 13Teeth","offer_id":52442836762898,"sku":"GLFBLFFGLBZSJ058108x1","price":19.27,"currency_code":"USD","in_stock":true},{"title":"2.5Mod 14Teeth","offer_id":52442836795666,"sku":"GLFBLFFGLBZSJ058109x1","price":21.11,"currency_code":"USD","in_stock":true},{"title":"2.5Mod 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