{"product_id":"4-mod-spur-gear-40mm-45-steel-12t-48t-cnc","title":"4 Modul 12T-60T Teeth 40mm Thick 45# Steel Spur Gears Pinion Gear For 3D CNC","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\n  \u003cdiv class=\"hdiy-overview\"\u003e\n    \u003ch2\u003eModule 4 Spur Gears in 45# Steel — Precision Drive Components for CNC \u0026amp; 3D Machinery\u003c\/h2\u003e\n    \u003cp\u003eWhen a mismatched or undersized gear causes backlash, premature wear, or unexpected downtime on your CNC router, 3D printer frame, or industrial drive train, the fix starts with selecting the right module 4 spur gear. These module 4 spur gears are engineered for makers, machine builders, and automation engineers who need dimensionally accurate, drop-in replacements or new-build drive components without compromise.\u003c\/p\u003e\n    \u003cp\u003eEach gear is machined from 45# medium-carbon steel — a material known for its balanced hardness and toughness — and features a 40 mm (approximately 1.57 in) face width. The tooth count range spans 12 T through 48 T, with pitch diameter scaling from approximately 48 mm (1.89 in) for the 12-tooth variant up to approximately 192 mm (7.56 in) for the 48-tooth variant. Bore diameter and keyway dimensions vary by tooth count; see variant options for confirmed bore specs.\u003c\/p\u003e\n    \u003cp\u003eTypical use cases include rack-and-pinion linear motion systems for CNC gantry axes, gear-reduction stages in 3D printer extruder drives, and rotary indexing tables in light industrial automation — all applications where a module 4 spur gear with a 40 mm face width delivers the torque capacity and positional accuracy the job demands.\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 any standard Module 4 (Mod 4) rack, pinion, or mating gear. Confirm bore diameter and keyway against your shaft spec before ordering.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-features\"\u003e\n    \u003ch2\u003e✅ Key Features of These Module 4 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 reliable balance of tensile strength and machinability, suitable for moderate-to-high load drive applications without the brittleness of fully hardened alloys.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\n        \u003cstrong\u003e40 mm Face Width for Increased Load Capacity\u003c\/strong\u003e — A wider face distributes tooth load across a larger contact area, reducing surface stress and extending service life compared to narrower gears of the same module.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🎯\u003c\/span\u003e\n        \u003cstrong\u003eModule 4 Standard Tooth Profile\u003c\/strong\u003e — Conforms to the ISO\/DIN module 4 involute tooth form, ensuring predictable mesh with any standard Mod 4 counterpart — rack, pinion, or mating spur gear.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🔢\u003c\/span\u003e\n        \u003cstrong\u003eWide Tooth-Count Selection (12 T – 48 T)\u003c\/strong\u003e — Choose the exact tooth count your gear ratio requires. Available in 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 38, 40, 42, 44, 45, 46, and 48 teeth.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🏭\u003c\/span\u003e\n        \u003cstrong\u003eMachined Bore \u0026amp; Keyway Ready\u003c\/strong\u003e — Each gear ships with a machined central bore sized to the tooth count variant. Keyway slot accommodates standard parallel keys for positive torque transmission without slippage.\n      \u003c\/li\u003e\n      \u003cli\u003e\n        \u003cspan class=\"hdiy-icon\"\u003e🔄\u003c\/span\u003e\n        \u003cstrong\u003eSuitable for CNC, 3D Printing \u0026amp; Automation Builds\u003c\/strong\u003e — Verified fit for rack-and-pinion CNC gantry axes, extruder gear-reduction stages, rotary indexing drives, and general-purpose power transmission where a Mod 4 spur gear is specified.\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 — Module 4 Spur Gear\u003c\/h2\u003e\n    \u003ctable\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003cth\u003eModule (Mod)\u003c\/th\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eTooth Count Range\u003c\/th\u003e\n\u003ctd\u003e12 T – 48 T (see variant options)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eFace Width\u003c\/th\u003e\n\u003ctd\u003e40 mm (≈ 1.57 in)\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\u003eTooth Profile\u003c\/th\u003e\n\u003ctd\u003eInvolute, 20° pressure angle\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003ePitch Diameter\u003c\/th\u003e\n\u003ctd\u003eModule × Teeth (e.g., 4 × 20 = 80 mm)\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\u003eSurface Finish\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eQuantity per Order\u003c\/th\u003e\n\u003ctd\u003e1 Pcs (default); bulk options available\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\u003eCalculate your required gear ratio first: divide the driver tooth count by the driven tooth count. For a CNC gantry axis, match the pinion tooth count to your rack pitch and motor torque spec. A lower tooth count (12–20 T) gives a smaller pitch diameter and higher rotational speed; a higher tooth count (30–48 T) increases pitch diameter and torque multiplication. Use the formula: Pitch Diameter = Module × Teeth (e.g., 4 × 20 = 80 mm).\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat load can these module 4 spur gears handle?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003e45# steel has a typical tensile strength of approximately 600–800 MPa depending on heat treatment. The 40 mm face width distributes tooth load effectively for moderate-to-high torque applications. Exact load ratings depend on operating speed, lubrication, and duty cycle. For heavy continuous-duty industrial use, consult a mechanical engineer to verify the safety factor for your specific application.\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 offers moderate corrosion resistance. For environments with moisture, coolant exposure, or outdoor use, we recommend applying a light machine oil or grease coating during operation, or specifying a surface-treated variant. If corrosion resistance is a primary requirement, consider stainless steel or nylon gears for your application.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWill this gear mesh with my existing Module 4 rack or pinion?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes — any gear or rack manufactured to the Module 4 (Mod 4) standard with a 20° pressure angle will mesh correctly with these gears. Verify that the mating component is also Module 4; mixing modules (e.g., Mod 3 with Mod 4) will result in incorrect mesh and accelerated wear.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat bore diameter and keyway size does each variant have?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eBore diameter and keyway dimensions vary by tooth count to maintain appropriate hub wall thickness. Please refer to the variant detail page or contact us to confirm the exact bore and keyway dimensions for your selected tooth count before ordering, especially if you are fitting the gear to a specific shaft diameter.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eCan I use these gears in a 3D printer extruder drive?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eModule 4 gears are on the larger end of the spectrum for desktop 3D printer extruders, which more commonly use Mod 0.5–1 gears. However, for large-format 3D printers, industrial FDM machines, or custom extruder gear-reduction stages where a Mod 4 gear is specified, these are a direct fit. Confirm your extruder's gear module before ordering.\u003c\/p\u003e\u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eDo I need to lubricate these gears during operation?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes, lubrication is recommended for all steel spur gear applications. Apply a suitable gear grease or machine oil to the tooth flanks during initial installation and re-lubricate at regular maintenance intervals. Proper lubrication reduces tooth wear, lowers operating temperature, and significantly extends gear service life.\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 \u003cstrong\u003eModulus \u0026amp; Teeth\u003c\/strong\u003e combination 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\": \"Calculate your required gear ratio first: divide the driver tooth count by the driven tooth count. Use the formula Pitch Diameter = Module × Teeth (e.g., 4 × 20 = 80 mm). Lower tooth counts give smaller pitch diameter and higher speed; higher tooth counts increase torque multiplication.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What load can these module 4 spur gears handle?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"45# steel has a typical tensile strength of approximately 600–800 MPa. The 40 mm face width distributes tooth load effectively for moderate-to-high torque applications. Exact load ratings depend on operating speed, lubrication, and duty cycle.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Are these gears corrosion-resistant?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"45# carbon steel offers moderate corrosion resistance. Apply a light machine oil or grease coating during operation for environments with moisture or coolant exposure.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will this gear mesh with my existing Module 4 rack or pinion?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — any gear or rack manufactured to the Module 4 (Mod 4) standard with a 20° pressure angle will mesh correctly with these gears.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What bore diameter and keyway size does each variant have?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Bore diameter and keyway dimensions vary by tooth count. Please contact us to confirm the exact bore and keyway dimensions for your selected tooth count before ordering.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I use these gears in a 3D printer extruder drive?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Module 4 gears are on the larger end for desktop 3D printers. For large-format or industrial FDM machines where Mod 4 is specified, these are a direct fit. Confirm your extruder's gear module before ordering.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Do I need to lubricate these gears during operation?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. Apply a suitable gear grease or machine oil to the tooth flanks during initial installation and re-lubricate at regular maintenance intervals to reduce wear and extend service life.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"HomeDIYer","offers":[{"title":"4 Mod 12 Teeth \/ 1 Pcs","offer_id":52442746323218,"sku":"GLFBQLWJGJXCD1224x1","price":71.13,"currency_code":"USD","in_stock":true},{"title":"4 Mod 13 Teeth \/ 1 Pcs","offer_id":52442746355986,"sku":"GLFBQLWJGJXCD1225x1","price":80.1,"currency_code":"USD","in_stock":true},{"title":"4 Mod 14 Teeth \/ 1 Pcs","offer_id":52442746388754,"sku":"GLFBQLWJGJXCD1226x1","price":88.92,"currency_code":"USD","in_stock":true},{"title":"4 Mod 15 Teeth \/ 1 Pcs","offer_id":52442746421522,"sku":"GLFBQLWJGJXCD1227x1","price":98.98,"currency_code":"USD","in_stock":true},{"title":"4 Mod 16 Teeth \/ 1 Pcs","offer_id":52442746454290,"sku":"GLFBQLWJGJXCD1228x1","price":108.77,"currency_code":"USD","in_stock":true},{"title":"4 Mod 17 Teeth \/ 1 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