{"product_id":"mod-2-bevel-gear-c45-steel-1-1-25-ratio-20-25-tooth-12-20mm-bore-hardened-black","title":"Mod 2 Bevel Gear C45 Steel 1:1.25 Ratio 20\/25 Tooth 12-20mm Bore Hardened Black","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003eMod 2 Bevel Gear C45 Steel — Heavy-Duty 1:1.25 Ratio Drive with Keyway Bore\u003c\/h2\u003e\n\u003cp\u003eWhen your drivetrain demands a larger, more robust bevel gear that can handle real torque loads without slipping on the shaft, a standard bore gear simply won't cut it. These Mod 2 bevel gears are built for engineers, machine builders, and serious makers who need a keyed shaft connection, a larger tooth profile, and a hardened finish that stands up to continuous mechanical stress. Whether you're designing a gearbox, upgrading a conveyor drive, or building a custom automation rig, the Mod 2 bevel gear delivers the shaft security and tooth strength the job requires.\u003c\/p\u003e\n\u003cp\u003eEach gear is machined from C45 medium-carbon steel and finished with a hardened black oxide surface treatment. Available in two tooth counts — 20 tooth and 25 tooth — forming a 1:1.25 gear ratio pair. Bore sizes range from 12mm to 20mm (approximately 0.47\" to 0.79\"), all with integrated keyways (4mm or 5mm or 6mm depending on bore size) for positive shaft locking. The Module (Mod) value is 2, meaning the tooth pitch is twice that of Mod 1, making these gears suited for higher-load applications. Outer diameter varies by tooth count: the 20-tooth gear measures approximately 44mm (~1.73\"), and the 25-tooth gear approximately 54mm (~2.13\").\u003c\/p\u003e\n\u003cp\u003eTypical use cases include industrial gearbox assemblies requiring a keyed Mod 2 bevel gear set, robotics and automation joints where shaft slip under load is unacceptable, and custom machinery drives where a 1:1.25 speed reduction with a hardened steel bevel gear and metric keyway bore is specified. These gears are also well-suited for agricultural equipment drives, conveyor angle drives, and CNC machine tool heads.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-compat\"\u003e\n\u003cspan class=\"hdiy-compat-icon\"\u003e⚙️\u003c\/span\u003e \u003cstrong\u003eCompatibility:\u003c\/strong\u003e Designed for Module 2 (Mod 2) gear systems. Pairs as a matched 20T\/25T bevel set for a 1:1.25 ratio. Bore sizes 12mm through 20mm include integrated keyways — confirm your shaft diameter and keyway dimensions before ordering. Not compatible with Mod 1 gears.\u003c\/div\u003e\n\u003ch2\u003e✅ Key Features of These Mod 2 Bevel Gears\u003c\/h2\u003e\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"hdiy-icon\"\u003e⚙️\u003c\/div\u003e\n\u003cstrong\u003eModule 2 Tooth Profile\u003c\/strong\u003e\n\u003cp\u003eMod 2 gears have a larger tooth pitch than Mod 1, providing greater tooth contact area and load-carrying capacity — suited for medium-to-heavy duty mechanical drive applications.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"hdiy-icon\"\u003e🔩\u003c\/div\u003e\n\u003cstrong\u003eC45 Steel Construction\u003c\/strong\u003e\n\u003cp\u003eMachined from C45 medium-carbon steel, offering a solid balance of machinability, tensile strength, and wear resistance for demanding mechanical drive environments.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"hdiy-icon\"\u003e🖤\u003c\/div\u003e\n\u003cstrong\u003eHardened Black Oxide Finish\u003c\/strong\u003e\n\u003cp\u003eSurface-hardened with a black oxide treatment that improves corrosion resistance, reduces surface friction, and extends service life under repeated load cycling.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"hdiy-icon\"\u003e🔑\u003c\/div\u003e\n\u003cstrong\u003eIntegrated Keyway Bore\u003c\/strong\u003e\n\u003cp\u003eAll bore variants include a machined keyway (4mm, 5mm, or 6mm depending on bore size), providing a positive mechanical lock to the shaft and eliminating rotational slip under torque.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"hdiy-icon\"\u003e📐\u003c\/div\u003e\n\u003cstrong\u003e1:1.25 Matched Ratio Pair\u003c\/strong\u003e\n\u003cp\u003eThe 20-tooth and 25-tooth gears work together as a matched bevel pair, delivering a precise 1:1.25 speed reduction or increase depending on which gear is the driver.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"hdiy-icon\"\u003e📦\u003c\/div\u003e\n\u003cstrong\u003eFlexible Pack Quantities\u003c\/strong\u003e\n\u003cp\u003eOrder in quantities of 1, 2, 3, 4, or 5 pieces to match your project scale — from a single replacement gear to a batch for a production build.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ch2\u003e📐 Technical Specifications — Mod 2 Bevel Gear\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eModule (Mod)\u003c\/th\u003e\n\u003ctd\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eGear Ratio\u003c\/th\u003e\n\u003ctd\u003e1:1.25 (20T drives 25T)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTooth Counts Available\u003c\/th\u003e\n\u003ctd\u003e20 Tooth \/ 25 Tooth\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore Sizes Available\u003c\/th\u003e\n\u003ctd\u003e12mm \/ 14mm \/ 15mm \/ 16mm \/ 18mm \/ 20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eKeyway Sizes\u003c\/th\u003e\n\u003ctd\u003e4mm (12mm bore) \/ 5mm (14–16mm bore) \/ 6mm (18–20mm bore)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eC45 Medium-Carbon Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSurface Treatment\u003c\/th\u003e\n\u003ctd\u003eHardened Black Oxide\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOuter Diameter (20T)\u003c\/th\u003e\n\u003ctd\u003eApprox. 44mm (~1.73\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOuter Diameter (25T)\u003c\/th\u003e\n\u003ctd\u003eApprox. 54mm (~2.13\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePressure Angle\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\u003ePack Quantities\u003c\/th\u003e\n\u003ctd\u003e1 \/ 2 \/ 3 \/ 4 \/ 5 pcs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-faq\"\u003e\n\u003ch2\u003e❓ Frequently Asked Questions\u003c\/h2\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat is the difference between Mod 1 and Mod 2 bevel gears?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThe Module number defines the tooth size — Mod 2 teeth are twice the size of Mod 1 teeth. Larger teeth mean greater load-carrying capacity and are better suited for higher-torque applications. Mod 1 and Mod 2 gears cannot mesh with each other. Always ensure all gears in your drivetrain share the same module number.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do I choose between the 20-tooth and 25-tooth gear?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThe 20-tooth and 25-tooth gears are designed as a matched pair for a 1:1.25 ratio. Drive the 20-tooth gear to reduce output speed and increase torque. Drive the 25-tooth gear to increase output speed and reduce torque. For a 1:1 ratio, two gears of the same tooth count are needed, which is a different product.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhich bore and keyway size should I select?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eSelect the bore size that matches your shaft diameter exactly. The keyway size is fixed per bore: 12mm bore uses a 4mm keyway, 14–16mm bores use a 5mm keyway, and 18–20mm bores use a 6mm keyway. Confirm your shaft's keyway dimensions match before ordering. If you are unsure, contact us with your shaft specifications.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eAre these gears strong enough for industrial or heavy-duty use?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eC45 steel has a tensile strength typically in the range of 600–800 MPa depending on heat treatment. The Mod 2 tooth profile provides greater contact area than Mod 1, making these gears suitable for medium-to-heavy duty mechanical drives, industrial gearboxes, and automation systems. For continuous high-load or high-RPM duty cycles, consult a mechanical engineer to verify the gear's rated torque capacity against your application requirements.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWill the black oxide finish protect against rust?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eBlack oxide provides moderate corrosion resistance compared to bare steel, but it is not a fully waterproof coating. For outdoor, wet, or high-humidity environments, apply a light machine oil or grease to the gear teeth and bore after installation. This will significantly extend service life in challenging conditions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I buy just one gear, or do I need to purchase the pair?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eEach tooth count variant is sold separately. You can purchase either the 20-tooth or the 25-tooth gear individually. If you need a complete 1:1.25 bevel gear pair, add one of each tooth count to your cart, ensuring the bore sizes match your respective shaft diameters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eAre bulk pack discounts available?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eYes — this listing offers quantity options of 1, 2, 3, 4, and 5 pieces per order. The per-unit price decreases as quantity increases, making larger packs the most cost-effective choice for production builds or stocking spare gears. Select your preferred quantity in the Amount option above.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-cta\"\u003e🛒 Select your Model (tooth count), Bore Size, and Amount above, then add to cart.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"HomeDIYer","offers":[{"title":"Module 2【20 Tooth】 \/ 12mm + 4mm Keyway \/ 1 pcs","offer_id":52439362961682,"sku":"PENGDZ00193x1","price":8.96,"currency_code":"USD","in_stock":true},{"title":"Module 2【20 Tooth】 \/ 14mm + 5mm Keyway \/ 1 pcs","offer_id":52439362994450,"sku":"PENGDZ00194x1","price":8.96,"currency_code":"USD","in_stock":true},{"title":"Module 2【20 Tooth】 \/ 15mm + 5mm Keyway \/ 1 pcs","offer_id":52439363027218,"sku":"PENGDZ00195x1","price":8.96,"currency_code":"USD","in_stock":true},{"title":"Module 2【20 Tooth】 \/ 16mm + 5mm Keyway \/ 1 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