{"product_id":"spur-gear-45-steel-1-module-27-teeth-pinion-motor-gear","title":"Spur Gear 45# Steel Transmission Gear 1 Module 27 Teeth Pinion Motor Gear","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\n  \u003cdiv class=\"hdiy-overview\"\u003e\n    \u003ch2\u003e1 Module 27 Teeth Spur Gear — Reliable 45# Steel Pinion for Precision Drive Systems\u003c\/h2\u003e\n    \u003cp\u003eWhen a slipping or worn pinion gear brings your motor-driven project to a halt, you need a replacement that fits right and holds up under load. Whether you're a robotics builder, CNC hobbyist, or mechanical engineer sourcing transmission components, this 1 Module 27 Teeth spur gear delivers the dimensional accuracy and material strength your drivetrain demands.\u003c\/p\u003e\n    \u003cp\u003eThis spur gear is machined from 45# medium-carbon steel, offering a balanced combination of toughness and machinability. With a module of 1 and 27 teeth, the pitch diameter is 27 mm (approximately 1.06 in), and the overall gear diameter is typically 29 mm (approx. 1.14 in). The bore diameter varies by variant — see variant options for exact bore sizing. Each pack contains 20 pieces, making it ideal for batch builds and spare-parts inventory.\u003c\/p\u003e\n    \u003cp\u003eTypical use cases include DC motor pinion replacement in robotics arms and automated feeders, gear-train assemblies in small CNC routers and laser engravers, and educational mechatronics kits requiring standardized metric module gears. Long-tail applications such as \"1 mod 27 tooth steel spur gear for robot\" and \"metric module 1 pinion gear 27T\" are well served by this component.\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 Fits any shaft or mating gear using Module 1 (Mod 1) metric standard. Pairs with M1 rack gears, M1 worm gears, and M1 spur gears of any tooth count. Verify bore diameter against your motor shaft before ordering.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-features\"\u003e\n    \u003ch2\u003e✅ Key Features of These 1 Module 27 Teeth Spur Gears\u003c\/h2\u003e\n    \u003cul class=\"hdiy-list\"\u003e\n      \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e\u003cstrong\u003e45# Medium-Carbon Steel Construction\u003c\/strong\u003e — Provides the tensile strength needed for continuous-duty motor applications without the brittleness of hardened tool steel.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\u003cstrong\u003eModule 1 \/ 27-Tooth Precision Profile\u003c\/strong\u003e — Hobbed tooth form ensures smooth mesh, low backlash, and quiet operation when paired with any other M1 gear.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🛡️\u003c\/span\u003e\u003cstrong\u003eCorrosion-Resistant Surface Finish\u003c\/strong\u003e — Treated surface reduces oxidation during storage and operation in moderately humid environments.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📦\u003c\/span\u003e\u003cstrong\u003e20-Piece Pack for Batch Builds\u003c\/strong\u003e — Stock your workshop or production line with enough spares to keep projects moving without repeated reorders.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🎯\u003c\/span\u003e\u003cstrong\u003eStandardized Metric Dimensions\u003c\/strong\u003e — Pitch diameter 27 mm, pressure angle 20°, and module 1 conform to ISO\/DIN metric gear standards for drop-in interchangeability.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔄\u003c\/span\u003e\u003cstrong\u003eWide Application Range\u003c\/strong\u003e — Suitable for DC motors, stepper motor pinions, gearbox stages, robotics joints, and educational mechatronics assemblies.\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-table-wrap\"\u003e\n    \u003ch2\u003e📐 Technical Specifications — Spur Gear\u003c\/h2\u003e\n    \u003ctable\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003cth\u003eModule\u003c\/th\u003e\n\u003ctd\u003e1 (Mod 1)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eNumber of Teeth\u003c\/th\u003e\n\u003ctd\u003e27\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003ePitch Diameter\u003c\/th\u003e\n\u003ctd\u003e27 mm (1.06 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eOutside Diameter\u003c\/th\u003e\n\u003ctd\u003e29 mm (1.14 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 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\u003eSee variant options\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\u003eCorrosion-resistant treated\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eGear Standard\u003c\/th\u003e\n\u003ctd\u003eISO\/DIN Metric Module\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003ePack Quantity\u003c\/th\u003e\n\u003ctd\u003e20 Pcs\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 diameter for my motor shaft?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eMeasure your motor shaft diameter with a caliper before ordering. The bore of the gear must match or be slightly larger than the shaft so a set screw or keyway can secure it. Check the variant options on this listing for available bore sizes and select the one closest to your shaft diameter.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat is Module 1 and is it compatible with my existing gears?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eModule (Mod) is the metric standard for gear tooth size. Module 1 means the pitch diameter in millimeters equals the number of teeth — so a 27-tooth M1 gear has a 27 mm pitch diameter. Any two gears of the same module and pressure angle (20° here) will mesh correctly, regardless of tooth count. If your existing gears are labeled M1 or Mod 1, these are compatible.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eHow strong is 45# steel — can it handle continuous motor load?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003e45# steel (equivalent to AISI 1045) has a tensile strength of approximately 600–700 MPa in its normalized state. It is well-suited for moderate-to-high torque pinion applications such as DC gear motors, stepper drives, and small gearboxes. For very high-shock or high-RPM applications, consider whether a hardened or alloy steel variant would better suit your load requirements.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWill these gears rust if stored or used in a humid environment?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThe gears have a corrosion-resistant surface treatment that provides protection during normal storage and use in moderately humid conditions. For outdoor or wet environments, applying a light machine oil or grease to the tooth surfaces is recommended to extend service life.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eCan I use these as a direct replacement for a worn pinion on a DC motor?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes, provided your motor's output shaft matches one of the available bore diameters and the mating gear on your drivetrain is also Module 1 with a 20° pressure angle. Confirm the face width and overall length fit within your gearbox housing before installing.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhy buy a 20-piece pack — what if I only need one gear?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThe 20-piece pack is designed for builders, educators, and small-batch manufacturers who need spares on hand or are assembling multiple units. Having extras prevents project downtime when a gear wears or a prototype needs iteration. If you need a smaller quantity, contact us to discuss options.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat tools do I need to install a spur gear onto a motor shaft?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eTypically you will need a hex key (Allen wrench) to tighten the set screw if the gear uses a set-screw bore, or a gear puller and press for interference-fit installations. A caliper is useful for verifying shaft and bore dimensions before assembly. No special tools are required beyond standard workshop equipment.\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 bore diameter and 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 diameter for my motor shaft?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Measure your motor shaft diameter with a caliper before ordering. The bore of the gear must match or be slightly larger than the shaft so a set screw or keyway can secure it. Check the variant options on this listing for available bore sizes and select the one closest to your shaft diameter.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is Module 1 and is it compatible with my existing gears?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Module (Mod) is the metric standard for gear tooth size. Module 1 means the pitch diameter in millimeters equals the number of teeth — so a 27-tooth M1 gear has a 27 mm pitch diameter. Any two gears of the same module and pressure angle (20°) will mesh correctly, regardless of tooth count.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How strong is 45# steel — can it handle continuous motor load?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"45# steel (equivalent to AISI 1045) has a tensile strength of approximately 600–700 MPa in its normalized state. It is well-suited for moderate-to-high torque pinion applications such as DC gear motors, stepper drives, and small gearboxes.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will these gears rust if stored or used in a humid environment?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The gears have a corrosion-resistant surface treatment that provides protection during normal storage and use in moderately humid conditions. For outdoor or wet environments, applying a light machine oil or grease to the tooth surfaces is recommended.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I use these as a direct replacement for a worn pinion on a DC motor?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes, provided your motor's output shaft matches one of the available bore diameters and the mating gear on your drivetrain is also Module 1 with a 20° pressure angle. Confirm the face width and overall length fit within your gearbox housing before installing.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Why buy a 20-piece pack — what if I only need one gear?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The 20-piece pack is designed for builders, educators, and small-batch manufacturers who need spares on hand or are assembling multiple units. Having extras prevents project downtime when a gear wears or a prototype needs iteration.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What tools do I need to install a spur gear onto a motor shaft?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Typically you will need a hex key to tighten the set screw if the gear uses a set-screw bore, or a gear puller and press for interference-fit installations. A caliper is useful for verifying shaft and bore dimensions before assembly.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"HomeDIYer","offers":[{"title":"1 Mod 27 Teeth \/ 20 Pcs","offer_id":52442281246994,"sku":"GLFBBYWJGJXCD0232x20","price":183.6,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Main-01_b0116bcf-85ac-40c7-99fd-f0d2e7380f60.jpg?v=1783412097","url":"https:\/\/homediyer.com\/products\/spur-gear-45-steel-1-module-27-teeth-pinion-motor-gear","provider":"HomeDIYer","version":"1.0","type":"link"}