{"product_id":"2-5-module-pinion-spur-gears-45-steel-metal-no-step-cnc-transmission","title":"2.5 Module Pinion Spur Gears #45 Steel Metal No-step CNC Transmission","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\n  \u003cdiv class=\"hdiy-overview\"\u003e\n    \u003ch2\u003e2.5 Module Spur Gears — Precision #45 Steel Pinion for CNC \u0026amp; Automation Drives\u003c\/h2\u003e\n    \u003cp\u003eWhen a slipping or undersized gear throws off your entire motion-control build, every axis suffers. Makers, CNC builders, and automation engineers who need repeatable, backlash-minimized power transfer rely on accurately machined spur gears — not off-spec castings. These 2.5 module pinion spur gears are designed for builders who demand dimensional consistency across every tooth.\u003c\/p\u003e\n    \u003cp\u003eEach gear is CNC-machined from #45 carbon steel with a no-step bore profile, available in tooth counts from 19T to 29T (module 2.5). Outer diameters range approximately from 52.5 mm (≈ 2.07 in) for 19T up to 77.5 mm (≈ 3.05 in) for 29T, with face widths typically 20–25 mm (≈ 0.79–0.98 in). Sold individually (1 Pcs per order).\u003c\/p\u003e\n    \u003cp\u003eTypical applications include CNC router X\/Y-axis rack-and-pinion drives, robotic arm joint transmission, conveyor indexing systems, and DIY gearbox builds requiring a 2.5M standard pitch. Long-tail use cases: \"2.5 module steel spur gear for CNC router\", \"45 steel pinion gear robotics\", \"no-step bore spur gear automation\".\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 Module 2.5 (2.5M) gear systems. Pairs with 2.5M racks, mating spur gears, and standard metric bore shafts. Verify shaft diameter and keyway requirements 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\u003e#45 Carbon Steel Construction\u003c\/strong\u003e — Machined from #45 medium-carbon steel for a strong balance of hardness and machinability, suitable for moderate-to-heavy load transmission without brittle failure.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🎯\u003c\/span\u003e\n        \u003cstrong\u003eNo-Step Bore Profile\u003c\/strong\u003e — Smooth, continuous bore without shoulder steps allows flexible shaft fitting and simplifies keyway or set-screw retention in custom assemblies.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🏭\u003c\/span\u003e\n        \u003cstrong\u003eCNC-Machined Tooth Form\u003c\/strong\u003e — Each tooth is CNC-cut to Module 2.5 involute profile standards, delivering consistent pitch accuracy and reduced noise during meshing.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\n        \u003cstrong\u003eWide Tooth-Count Selection\u003c\/strong\u003e — Available in 19T, 22T, 26T, 27T, 28T, and 29T to let you dial in the exact gear ratio needed for your drive system without custom fabrication.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🔄\u003c\/span\u003e\n        \u003cstrong\u003eStandard Metric Module Pitch\u003c\/strong\u003e — Module 2.5 is a widely adopted metric standard, making these gears interchangeable with compatible racks, pinions, and mating gears from other metric-standard sources.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e📦\u003c\/span\u003e\n        \u003cstrong\u003eIndividually Packaged (1 Pcs)\u003c\/strong\u003e — Each unit is sold and shipped as a single gear, letting you order exactly the tooth count and quantity your project requires without overstocking.\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 Gears\u003c\/h2\u003e\n    \u003ctable\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003cth\u003eModule\u003c\/th\u003e\n\u003ctd\u003e2.5M\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003e#45 Carbon Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eTooth Count Options\u003c\/th\u003e\n\u003ctd\u003e19T, 22T, 26T, 27T, 28T, 29T\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eOuter Diameter (OD)\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\u003eFace Width\u003c\/th\u003e\n\u003ctd\u003eTypically 20–25 mm (≈ 0.79–0.98 in)\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\u003eBore Profile\u003c\/th\u003e\n\u003ctd\u003eNo-step (smooth continuous bore)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eFinish\u003c\/th\u003e\n\u003ctd\u003eNatural steel \/ lightly oiled\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003ePacking Quantity\u003c\/th\u003e\n\u003ctd\u003e1 Pcs\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      \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\u003eSelect the tooth count based on your required gear ratio. Divide the driven gear's tooth count by the driving gear's tooth count to get the ratio. For example, pairing a 19T pinion with a 38T gear gives a 2:1 reduction. Use smaller tooth counts (19T–22T) for higher reduction ratios and larger counts (26T–29T) for closer to 1:1 drives or overdrive setups.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat shaft diameter does the bore fit?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThe bore diameter varies by tooth count variant. Please refer to the variant options or contact us to confirm the exact bore size before ordering. The no-step bore design allows for set-screw or keyway retention depending on your shaft configuration.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eAre these gears strong enough for CNC router rack-and-pinion drives?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003e#45 carbon steel provides solid tensile strength suitable for CNC router X\/Y-axis rack-and-pinion applications under typical cutting loads. For very high-speed or heavy-duty industrial applications with continuous shock loading, consider whether a hardened or alloy steel gear would better suit your torque requirements.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eDo these gears resist rust and corrosion?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003e#45 carbon steel is not inherently stainless. The gears are lightly oiled for transit protection. For environments with moisture, coolant exposure, or outdoor use, we recommend applying a rust-inhibiting coating, grease, or considering stainless steel alternatives for your application.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWill these mesh with gears or racks from other brands?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes — as long as the mating component is also Module 2.5 (2.5M) with a 20° pressure angle, these gears will mesh correctly regardless of brand. Always verify the module and pressure angle of your existing rack or mating gear before purchasing.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eCan I buy multiple tooth counts in one order?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eEach variant is sold individually (1 Pcs per line item). To order multiple tooth counts, simply add each desired variant to your cart separately. There is no minimum order quantity per variant.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat is the difference between module and pitch in gear sizing?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eModule is the metric standard for gear tooth size, defined as the pitch diameter divided by the number of teeth. A Module 2.5 gear has a tooth pitch of 2.5π mm (≈ 7.85 mm). Diametral Pitch (DP) is the imperial equivalent — Module 2.5 is approximately 10.16 DP. These gears use the metric Module 2.5 standard and should only be paired with other 2.5M components.\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 (Number of teeth) 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\": \"Select the tooth count based on your required gear ratio. Divide the driven gear's tooth count by the driving gear's tooth count to get the ratio. For example, pairing a 19T pinion with a 38T gear gives a 2:1 reduction. Use smaller tooth counts (19T–22T) for higher reduction ratios and larger counts (26T–29T) for closer to 1:1 drives or overdrive setups.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What shaft diameter does the bore fit?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The bore diameter varies by tooth count variant. Please refer to the variant options or contact us to confirm the exact bore size before ordering. The no-step bore design allows for set-screw or keyway retention depending on your shaft configuration.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Are these gears strong enough for CNC router rack-and-pinion drives?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"#45 carbon steel provides solid tensile strength suitable for CNC router X\/Y-axis rack-and-pinion applications under typical cutting loads. For very high-speed or heavy-duty industrial applications with continuous shock loading, consider whether a hardened or alloy steel gear would better suit your torque requirements.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Do these gears resist rust and corrosion?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"#45 carbon steel is not inherently stainless. The gears are lightly oiled for transit protection. For environments with moisture, coolant exposure, or outdoor use, we recommend applying a rust-inhibiting coating, grease, or considering stainless steel alternatives for your application.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will these mesh with gears or racks from other brands?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — as long as the mating component is also Module 2.5 (2.5M) with a 20° pressure angle, these gears will mesh correctly regardless of brand. Always verify the module and pressure angle of your existing rack or mating gear before purchasing.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I buy multiple tooth counts in one order?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Each variant is sold individually (1 Pcs per line item). To order multiple tooth counts, simply add each desired variant to your cart separately. There is no minimum order quantity per variant.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the difference between module and pitch in gear sizing?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Module is the metric standard for gear tooth size, defined as the pitch diameter divided by the number of teeth. A Module 2.5 gear has a tooth pitch of 2.5π mm (≈ 7.85 mm). Diametral Pitch (DP) is the imperial equivalent — Module 2.5 is approximately 10.16 DP. These gears use the metric Module 2.5 standard and should only be paired with other 2.5M components.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"HomeDIYer","offers":[{"title":"2.5M 19T \/ 1 Pcs","offer_id":52442526941458,"sku":"FAS058114x1","price":55.01,"currency_code":"USD","in_stock":true},{"title":"2.5M 22T \/ 1 Pcs","offer_id":52442526974226,"sku":"FAS058117x1","price":60.45,"currency_code":"USD","in_stock":true},{"title":"2.5M 26T \/ 1 Pcs","offer_id":52442527006994,"sku":"FAS058121x1","price":90.97,"currency_code":"USD","in_stock":true},{"title":"2.5M 27T \/ 1 Pcs","offer_id":52442527039762,"sku":"FAS058122x1","price":102.07,"currency_code":"USD","in_stock":true},{"title":"2.5M 28T \/ 1 Pcs","offer_id":52442527072530,"sku":"FAS058123x1","price":102.39,"currency_code":"USD","in_stock":true},{"title":"2.5M 29T \/ 1 Pcs","offer_id":52442527105298,"sku":"FAS058124x1","price":108.6,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture1of2_a13b5412-7e90-4afe-99dc-7b08e42ce2ea.jpg?v=1783563615","url":"https:\/\/homediyer.com\/products\/2-5-module-pinion-spur-gears-45-steel-metal-no-step-cnc-transmission","provider":"HomeDIYer","version":"1.0","type":"link"}