{"product_id":"mod-1-5-steel-spur-gear-20-teeth-bore-5mm-15mm-transmission-pinion-with-keyslot","title":"Mod 1.5 Steel Spur Gear 20 Teeth Bore 5mm-15mm Transmission Pinion with Keyslot","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\n  \u003cdiv class=\"hdiy-overview\"\u003e\n    \u003ch2\u003eMod 1.5 Steel Spur Gear 20T — Precision Transmission Pinion for Robotics, CNC \u0026amp; DIY Builds\u003c\/h2\u003e\n    \u003cp\u003eWhen your project demands reliable torque transfer and tight meshing tolerances, a poorly matched gear becomes the weakest link in your drivetrain. Whether you're a robotics engineer, CNC hobbyist, or RC vehicle builder, the Mod 1.5 steel spur gear with 20 teeth gives you the dimensional accuracy and material strength needed to keep your transmission running smoothly under load.\u003c\/p\u003e\n    \u003cp\u003eThis spur gear is machined from carbon steel, offering a solid balance of strength and machinability. The module (modulus) is 1.5, with 20 teeth and a pitch circle diameter of 30mm (approximately 1.18 inches). Bore sizes range from 5mm to 15mm (approximately 0.20 to 0.59 inches), with optional keyslot configurations (3×1.4mm, 4×1.8mm, or 5×2.3mm) available for positive shaft locking.\u003c\/p\u003e\n    \u003cp\u003eTypical use cases include DIY robotic arm joint drives requiring a compact Mod 1.5 spur gear set, CNC axis transmission systems needing a steel pinion gear with keyway, and RC vehicle gearbox builds where a 20-tooth steel spur gear with bore selection is essential for custom shaft fitment.\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 Meshes with all Mod 1.5 (Module 1.5) spur gears and racks. Verify bore size and keyslot requirement before ordering.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-features\"\u003e\n    \u003ch2\u003e✅ Key Features of These Mod 1.5 Steel Spur Gears\u003c\/h2\u003e\n    \u003cul class=\"hdiy-list\"\u003e\n      \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e\u003cstrong\u003eModule 1.5 Standard\u003c\/strong\u003e — Fully compatible with all Mod 1.5 mating gears and racks for reliable meshing in standard drivetrain assemblies.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🦾\u003c\/span\u003e\u003cstrong\u003eCarbon Steel Construction\u003c\/strong\u003e — Machined from carbon steel for strong torque transmission and resistance to deformation under mechanical load.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\u003cstrong\u003e20-Tooth Profile\u003c\/strong\u003e — 20T involute tooth form provides smooth engagement and consistent gear ratio in compact transmission layouts.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🎯\u003c\/span\u003e\u003cstrong\u003eMulti-Bore Options (5–15mm)\u003c\/strong\u003e — Choose from 10 bore diameter options (5mm, 6mm, 6.35mm, 7mm, 8mm, 10mm, 12mm, 12.7mm, 14mm, 15mm) to match your shaft exactly.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔑\u003c\/span\u003e\u003cstrong\u003eOptional Keyslot Configurations\u003c\/strong\u003e — Available with no keyslot or with 3×1.4mm, 4×1.8mm, or 5×2.3mm keyways for positive shaft-to-gear locking without slippage.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🏭\u003c\/span\u003e\u003cstrong\u003eBroad Application Range\u003c\/strong\u003e — Suitable for robotics joints, CNC axis drives, RC gearboxes, automation equipment, and custom DIY transmission builds.\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-table-wrap\"\u003e\n    \u003ch2\u003e📐 Technical Specifications — Mod 1.5 Spur Gear\u003c\/h2\u003e\n    \u003ctable\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003cth\u003eModule (Modulus)\u003c\/th\u003e\n\u003ctd\u003e1.5\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eNumber of Teeth\u003c\/th\u003e\n\u003ctd\u003e20T\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003ePitch Circle Diameter\u003c\/th\u003e\n\u003ctd\u003e30mm (approx. 1.18 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eOutside Diameter\u003c\/th\u003e\n\u003ctd\u003eTypically 33mm (approx. 1.30 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eBore Diameter\u003c\/th\u003e\n\u003ctd\u003e5 \/ 6 \/ 6.35 \/ 7 \/ 8 \/ 10 \/ 12 \/ 12.7 \/ 14 \/ 15mm — See variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eKeyslot\u003c\/th\u003e\n\u003ctd\u003eNone \/ 3×1.4mm \/ 4×1.8mm \/ 5×2.3mm — See variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eFace Width (Hub Length)\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\u003eCarbon Steel\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\u003ePressure Angle\u003c\/th\u003e\n\u003ctd\u003e20°\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eGear Type\u003c\/th\u003e\n\u003ctd\u003eSpur Gear (Pinion)\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      \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 bore size for my shaft?\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 your shaft exactly — options range from 5mm to 15mm (including 6.35mm and 12.7mm for imperial shafts). If your shaft is slightly undersized, a keyslot variant with a set screw can compensate for minor play.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eDo I need a keyslot version, or is the plain bore sufficient?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eFor light-duty or low-torque applications, a plain bore with a set screw is often adequate. For higher torque loads or applications where gear slippage would be critical (such as CNC axis drives or robotic joints), a keyslot version (3×1.4mm, 4×1.8mm, or 5×2.3mm) provides a positive mechanical lock between the gear and shaft.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat gears will this Mod 1.5 spur gear mesh with?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThis gear meshes with any other Mod 1.5 (Module 1.5) spur gear or rack with a matching 20° pressure angle. The module must match exactly — Mod 1.5 gears will not correctly mesh with Mod 1.0, Mod 2.0, or other module gears.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eIs carbon steel suitable for outdoor or humid environments?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eCarbon steel offers strong mechanical properties but has limited corrosion resistance compared to stainless steel. For outdoor or humid environments, we recommend applying a light machine oil or grease coating, or considering a surface-treated variant. For highly corrosive environments, contact us to confirm the best option for your application.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat is the gear ratio if I pair this 20T gear with another gear?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eGear ratio is calculated as the number of teeth on the driven gear divided by the number of teeth on the driving gear. For example, pairing this 20T pinion with a 40T gear gives a 2:1 reduction ratio. The Mod 1.5 standard ensures consistent center distance calculations: center distance = (T1 + T2) × Module \/ 2.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eCan I use this gear in a CNC machine or 3D printer extruder drive?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. Mod 1.5 steel spur gears are commonly used in CNC axis transmission systems and extruder gear trains. Verify that your mating gear is also Mod 1.5 and that the bore size matches your stepper motor shaft. For extruder applications, confirm the face width is sufficient for your filament drive requirements.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eHow do I determine which keyslot size to select?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eKeyslot size should match the keyway cut into your shaft. Common pairings: 3×1.4mm keyslot for smaller shafts (typically 8–10mm bore), 4×1.8mm for mid-range shafts (typically 10–12mm bore), and 5×2.3mm for larger shafts (typically 12–15mm bore). Always verify against your shaft's actual keyway dimensions 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 modulus, bore size, and keyslot option 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 for my shaft?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Measure your motor or drive shaft diameter with a caliper. Select the bore size that matches your shaft exactly — options range from 5mm to 15mm (including 6.35mm and 12.7mm for imperial shafts). If your shaft is slightly undersized, a keyslot variant with a set screw can compensate for minor play.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Do I need a keyslot version, or is the plain bore sufficient?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"For light-duty or low-torque applications, a plain bore with a set screw is often adequate. For higher torque loads or applications where gear slippage would be critical, a keyslot version provides a positive mechanical lock between the gear and shaft.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What gears will this Mod 1.5 spur gear mesh with?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"This gear meshes with any other Mod 1.5 (Module 1.5) spur gear or rack with a matching 20° pressure angle. The module must match exactly — Mod 1.5 gears will not correctly mesh with Mod 1.0, Mod 2.0, or other module gears.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is carbon steel suitable for outdoor or humid environments?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Carbon steel offers strong mechanical properties but has limited corrosion resistance. For outdoor or humid environments, apply a light machine oil or grease coating. For highly corrosive environments, contact us to confirm the best option.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the gear ratio if I pair this 20T gear with another gear?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Gear ratio = driven teeth ÷ driving teeth. Pairing this 20T pinion with a 40T gear gives a 2:1 reduction. Center distance = (T1 + T2) × Module \/ 2.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I use this gear in a CNC machine or 3D printer extruder drive?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. Mod 1.5 steel spur gears are commonly used in CNC axis transmission systems and extruder gear trains. Verify that your mating gear is also Mod 1.5 and that the bore size matches your stepper motor shaft.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How do I determine which keyslot size to select?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Keyslot size should match the keyway cut into your shaft. Common pairings: 3×1.4mm for 8–10mm bore shafts, 4×1.8mm for 10–12mm bore, and 5×2.3mm for 12–15mm bore. Always verify against your shaft's actual keyway dimensions before ordering.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"HomeDIYer","offers":[{"title":"1.5M-20T \/ 5mm \/ -","offer_id":52442116653330,"sku":"GLFBCQFGLCDPJ00027x1","price":17.82,"currency_code":"USD","in_stock":true},{"title":"1.5M-20T \/ 6mm \/ -","offer_id":52442116686098,"sku":"GLFBCQFGLBZSJ057854x1","price":17.82,"currency_code":"USD","in_stock":true},{"title":"1.5M-20T \/ 6.35mm \/ -","offer_id":52442116718866,"sku":"GLFBCQFGLBZSJ057855x1","price":18.09,"currency_code":"USD","in_stock":true},{"title":"1.5M-20T \/ 7mm \/ -","offer_id":52442116751634,"sku":"GLFBCQFGLBZSJ057856x1","price":17.82,"currency_code":"USD","in_stock":true},{"title":"1.5M-20T \/ 8mm \/ -","offer_id":52442116784402,"sku":"GLFBCQFGLBZSJ057857x1","price":17.82,"currency_code":"USD","in_stock":true},{"title":"1.5M-20T \/ 10mm \/ -","offer_id":52442116817170,"sku":"GLFBCQFGLBZSJ057858x1","price":17.82,"currency_code":"USD","in_stock":true},{"title":"1.5M-20T \/ 12mm \/ -","offer_id":52442116849938,"sku":"GLFBCQFGLBZSJ057859x1","price":18.47,"currency_code":"USD","in_stock":true},{"title":"1.5M-20T \/ 14mm \/ -","offer_id":52442116882706,"sku":"GLFBCQFGLBZSJ057860x1","price":18.47,"currency_code":"USD","in_stock":true},{"title":"1.5M-20T \/ 15mm \/ -","offer_id":52442116915474,"sku":"GLFBCQFGLBZSJ057861x1","price":18.47,"currency_code":"USD","in_stock":true},{"title":"1.5M-20T \/ 10mm \/ 3x1.4mm","offer_id":52442116948242,"sku":"GLFBCQFGLBZSJ057862x1","price":19.18,"currency_code":"USD","in_stock":true},{"title":"1.5M-20T \/ 12.7mm \/ 5x2.3mm","offer_id":52442116981010,"sku":"GLFBCQFGLBZSJ057863x1","price":19.18,"currency_code":"USD","in_stock":true},{"title":"1.5M-20T \/ 14mm \/ 5x2.3mm","offer_id":52442117013778,"sku":"GLFBCQFGLBZSJ057864x1","price":19.18,"currency_code":"USD","in_stock":true},{"title":"1.5M-20T \/ 15mm \/ 5x2.3mm","offer_id":52442117046546,"sku":"GLFBCQFGLBZSJ057865x1","price":19.18,"currency_code":"USD","in_stock":true},{"title":"1.5M-20T \/ 10mm \/ 4x1.8mm","offer_id":52442117079314,"sku":"GLFBCQFGLBZSJ057866x1","price":19.18,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Main-01_01cf4a24-5809-4537-a987-e7f7bfc5c795.jpg?v=1783408263","url":"https:\/\/homediyer.com\/products\/mod-1-5-steel-spur-gear-20-teeth-bore-5mm-15mm-transmission-pinion-with-keyslot","provider":"HomeDIYer","version":"1.0","type":"link"}