{"product_id":"mod-1-1-5-2-bevel-gear-c45-steel-ratio-1-1-25-20-tooth-25-tooth-hardened-black","title":"Mod 1 1.5 2 Bevel Gear C45 Steel Ratio 1:1.25 20 Tooth 25 Tooth Hardened Black","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003eC45 Steel Bevel Gear — Mod 1\/1.5\/2, 20 \u0026amp; 25 Tooth, Hardened Black Finish for Reliable Right-Angle Power Transmission\u003c\/h2\u003e\n\u003cp\u003eWhen a motion system demands a precise 90° direction change without slipping or backlash creep, the wrong gear ruins the whole build. Hobbyists assembling CNC routers, engineers prototyping robotic joints, and makers building custom drive trains all need a bevel gear they can trust to mesh cleanly and hold up under repeated load cycles.\u003c\/p\u003e\n\u003cp\u003eThese bevel gears are machined from C45 medium-carbon steel and surface-hardened with a black oxide finish for corrosion resistance and reduced light reflection. Available in three modules (Mod 1, Mod 1.5, Mod 2) and two tooth counts (20T and 25T), with bore sizes ranging from 6 mm (0.24 in) to 20 mm (0.79 in). Keyway options (4 mm or 5 mm or 6 mm depending on bore) are available on Mod 2 variants for positive shaft locking.\u003c\/p\u003e\n\u003cp\u003eTypical use cases include right-angle gearbox assemblies in CNC router Z-axis drives, bevel gear pairs for robotic arm wrist joints, and custom differential gear sets in RC vehicle and automation projects requiring compact 1:1.25 ratio power transfer.\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 to mesh as matched pairs (20T × 25T) at a 1:1.25 ratio. Gears of the same module mesh together. Confirm module, tooth count, and bore diameter before ordering. Keyway variants require a matching keyed shaft.\u003c\/div\u003e\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003ch2\u003e✅ Key Features of These C45 Steel Bevel Gears\u003c\/h2\u003e\n\u003cdiv class=\"hdiy-list\"\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e \u003cstrong\u003eC45 Medium-Carbon Steel Construction\u003c\/strong\u003e\n\u003cp\u003eMachined from C45 steel for a balance of machinability and tensile strength, suitable for moderate-to-high torque right-angle drives.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🖤\u003c\/span\u003e \u003cstrong\u003eBlack Oxide Surface Hardening\u003c\/strong\u003e\n\u003cp\u003eThe hardened black finish reduces surface friction, provides mild corrosion resistance, and minimises glare in exposed drive assemblies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e \u003cstrong\u003eThree Module Options (Mod 1 \/ 1.5 \/ 2)\u003c\/strong\u003e\n\u003cp\u003eSelect the module that matches your existing gear train. Larger modules carry higher loads; smaller modules suit compact, low-torque mechanisms.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔑\u003c\/span\u003e \u003cstrong\u003eKeyway Bore Options for Positive Shaft Lock\u003c\/strong\u003e\n\u003cp\u003eMod 2 variants offer keyway bores (4 mm, 5 mm, or 6 mm keyway) to prevent rotational slip under shock loads — critical for servo and motor shafts.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📏\u003c\/span\u003e \u003cstrong\u003eWide Bore Range: 6 mm – 20 mm\u003c\/strong\u003e\n\u003cp\u003eBore sizes from 6 mm (0.24 in) to 20 mm (0.79 in) cover the most common motor and shaft diameters used in DIY robotics and CNC builds.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e⚖️\u003c\/span\u003e \u003cstrong\u003e1:1.25 Gear Ratio (20T : 25T Pairing)\u003c\/strong\u003e\n\u003cp\u003eThe 20-tooth and 25-tooth pairing delivers a 1:1.25 speed reduction ratio, useful for modest torque multiplication in compact right-angle drives.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ch2\u003e📐 Technical Specifications — Bevel Gear\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\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\u003eBlack Oxide (Hardened)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eAvailable Modules\u003c\/th\u003e\n\u003ctd\u003eMod 1 \/ Mod 1.5 \/ Mod 2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTooth Count Options\u003c\/th\u003e\n\u003ctd\u003e20 Tooth \/ 25 Tooth\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eGear Ratio\u003c\/th\u003e\n\u003ctd\u003e1 : 1.25 (20T : 25T pair)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore Diameter Range\u003c\/th\u003e\n\u003ctd\u003e6 mm – 20 mm (0.24 in – 0.79 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eKeyway Options\u003c\/th\u003e\n\u003ctd\u003e4 mm \/ 5 mm \/ 6 mm (Mod 2 variants only)\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\u003ePitch Cone 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\u003eWeight\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 pc\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\u003eHow do I choose the right module for my project?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThe module must match between meshing gears. Mod 1 suits light-load, compact mechanisms (e.g., small robotics). Mod 1.5 is a mid-range choice for moderate torque. Mod 2 handles higher loads and is common in CNC and industrial-style DIY builds. Check your existing gear train or motor pinion module before selecting.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I use a 20-tooth gear with another 20-tooth gear?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eYes — two gears of the same module and tooth count will mesh at a 1:1 ratio. However, this product is designed and sold as a 1:1.25 ratio pair (20T driving 25T or vice versa). If you need a 1:1 ratio, order two 20-tooth gears of the same module.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eDo I need a keyway bore, and which keyway size should I choose?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eKeyway bores are only available on Mod 2 variants. A keyway is recommended when the shaft transmits shock loads or reversing torque, as it prevents the gear from spinning on the shaft. Match the keyway width to your shaft's existing keyway slot: 4 mm keyway for 12 mm bore, 5 mm keyway for 14–16 mm bore, and 6 mm keyway for 18–20 mm bore.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eIs C45 steel strong enough for my application?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eC45 steel has a tensile strength of approximately 600–800 MPa in its normalised state, rising after surface hardening. It is well-suited for moderate-torque right-angle drives in robotics, CNC, and automation. For very high-torque or continuous industrial duty, consider alloy steel gears (e.g., 40Cr). Contact us if you need load calculations for your specific application.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow corrosion-resistant is the black oxide finish?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eBlack oxide provides mild corrosion resistance suitable for indoor, dry environments. It is not a substitute for stainless steel or zinc plating in humid or outdoor conditions. For added protection, apply a light machine oil or grease to the gear surface after installation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat bore size should I order for my motor shaft?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eMeasure your motor or drive shaft diameter precisely with a calliper. Select the bore size that matches — a bore that is too large will cause runout and vibration. If your shaft has a keyway, choose the corresponding keyway bore variant (Mod 2 only). For plain shafts, a standard bore with a set-screw or locking collar is typical.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan these gears be used in a wet or lubricated environment?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThese gears can operate with light grease or oil lubrication, which is recommended for extended service life. Avoid submerging in water or exposing to corrosive fluids, as the black oxide finish offers only mild protection. For wet environments, consider stainless steel alternatives.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-cta\"\u003e🛒 Select your Module, 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 1【20 Tooth】 \/ 6mm \/ 1 pcs","offer_id":52439344808210,"sku":"PENGDZ00180x1","price":7.74,"currency_code":"USD","in_stock":true},{"title":"Module 1【20 Tooth】 \/ 8mm \/ 1 pcs","offer_id":52439344840978,"sku":"PENGDZ00181x1","price":7.74,"currency_code":"USD","in_stock":true},{"title":"Module 1【25 Tooth】 \/ 8mm \/ 1 pcs","offer_id":52439344873746,"sku":"PENGDZ00182x1","price":10.05,"currency_code":"USD","in_stock":true},{"title":"Module 1【25 Tooth】 \/ 10mm \/ 1 pcs","offer_id":52439344906514,"sku":"PENGDZ00183x1","price":10.05,"currency_code":"USD","in_stock":true},{"title":"Module 1【25 Tooth】 \/ 12mm \/ 1 pcs","offer_id":52439344939282,"sku":"PENGDZ00184x1","price":10.05,"currency_code":"USD","in_stock":true},{"title":"Module 1.5【20 Tooth】 \/ 8mm \/ 1 pcs","offer_id":52439344972050,"sku":"PENGDZ00185x1","price":9.1,"currency_code":"USD","in_stock":true},{"title":"Module 1.5【20 Tooth】 \/ 10mm \/ 1 pcs","offer_id":52439345004818,"sku":"PENGDZ00186x1","price":9.1,"currency_code":"USD","in_stock":true},{"title":"Module 1.5【20 Tooth】 \/ 12mm \/ 1 pcs","offer_id":52439345037586,"sku":"PENGDZ00187x1","price":9.1,"currency_code":"USD","in_stock":true},{"title":"Module 1.5【25 Tooth】 \/ 10mm \/ 1 pcs","offer_id":52439345070354,"sku":"PENGDZ00188x1","price":13.72,"currency_code":"USD","in_stock":true},{"title":"Module 1.5【25 Tooth】 \/ 12mm \/ 1 pcs","offer_id":52439345103122,"sku":"PENGDZ00189x1","price":13.72,"currency_code":"USD","in_stock":true},{"title":"Module 1.5【25 Tooth】 \/ 14mm \/ 1 pcs","offer_id":52439345135890,"sku":"PENGDZ00190x1","price":13.72,"currency_code":"USD","in_stock":true},{"title":"Module 1.5【25 Tooth】 \/ 15mm \/ 1 pcs","offer_id":52439345168658,"sku":"PENGDZ00191x1","price":13.72,"currency_code":"USD","in_stock":true},{"title":"Module 1.5【25 Tooth】 \/ 16mm \/ 1 pcs","offer_id":52439345201426,"sku":"PENGDZ00192x1","price":13.72,"currency_code":"USD","in_stock":true},{"title":"Module 2【20 Tooth】 \/ 12mm + 4mm Keyway \/ 1 pcs","offer_id":52439345234194,"sku":"PENGDZ00193x1","price":15.76,"currency_code":"USD","in_stock":true},{"title":"Module 2【20 Tooth】 \/ 14mm + 5mm Keyway \/ 1 pcs","offer_id":52439345266962,"sku":"PENGDZ00194x1","price":15.76,"currency_code":"USD","in_stock":true},{"title":"Module 2【20 Tooth】 \/ 15mm + 5mm Keyway \/ 1 pcs","offer_id":52439345299730,"sku":"PENGDZ00195x1","price":15.76,"currency_code":"USD","in_stock":true},{"title":"Module 2【20 Tooth】 \/ 16mm + 5mm Keyway \/ 1 pcs","offer_id":52439345332498,"sku":"PENGDZ00196x1","price":15.76,"currency_code":"USD","in_stock":true},{"title":"Module 2【25 Tooth】 \/ 14mm + 5mm Keyway \/ 1 pcs","offer_id":52439345365266,"sku":"PENGDZ00197x1","price":24.19,"currency_code":"USD","in_stock":true},{"title":"Module 2【25 Tooth】 \/ 15mm + 5mm Keyway \/ 1 pcs","offer_id":52439345398034,"sku":"PENGDZ00198x1","price":24.19,"currency_code":"USD","in_stock":true},{"title":"Module 2【25 Tooth】 \/ 16mm + 5mm Keyway \/ 1 pcs","offer_id":52439345430802,"sku":"PENGDZ00199x1","price":24.19,"currency_code":"USD","in_stock":true},{"title":"Module 2【25 Tooth】 \/ 18mm + 6mm Keyway \/ 1 pcs","offer_id":52439345463570,"sku":"PENGDZ00200x1","price":24.19,"currency_code":"USD","in_stock":true},{"title":"Module 2【25 Tooth】 \/ 20mm + 6mm Keyway \/ 1 pcs","offer_id":52439345496338,"sku":"PENGDZ00201x1","price":24.19,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture6of16_3adedcc3-655c-4e47-b3ff-1b0d1f97f9df.jpg?v=1783390564","url":"https:\/\/homediyer.com\/products\/mod-1-1-5-2-bevel-gear-c45-steel-ratio-1-1-25-20-tooth-25-tooth-hardened-black","provider":"HomeDIYer","version":"1.0","type":"link"}