{"product_id":"module-1-1-5-helical-gear-304-stainless-steel-45-left-hand-13-15-20t-teeth","title":"Module 1 1.5 Helical Gear 304 Stainless Steel 45° Left-hand 13\/15\/20T Teeth","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003eModule 1 \u0026amp; 1.5 Left-Hand Helical Gear — 304 Stainless Steel for Precision Motion Control\u003c\/h2\u003e\n\u003cp\u003eWhen your drive system demands smooth, low-noise power transmission and standard spur gears fall short, a left-hand helical gear delivers the angular engagement that reduces backlash and vibration. Designed for engineers, CNC builders, robotics enthusiasts, and automation hobbyists who need reliable torque transfer in compact mechanical assemblies.\u003c\/p\u003e\n\u003cp\u003eThese module 1 and 1.5 helical gears are machined from 304 stainless steel, offering solid corrosion resistance for both indoor and light outdoor applications. Available in 13T, 15T, and 20T tooth counts across Module 1 (pitch diameter range approximately 13–20mm \/ 0.51–0.79 in) and Module 1.5 (pitch diameter range approximately 15–30mm \/ 0.59–1.18 in). Bore options span 6mm to 16mm plain bore, plus keyed variants with 4mm and 5mm keyways for shaft-locking applications.\u003c\/p\u003e\n\u003cp\u003eTypical use cases include CNC router axis drives requiring left-hand helical pairing, robotics joint actuators where noise reduction is critical, and custom automation conveyor systems needing stainless-compatible gear trains.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-compat\"\u003e\n\u003cspan class=\"hdiy-compat-icon\"\u003e⚙️\u003c\/span\u003e Compatible with standard Module 1 and Module 1.5 gear systems. Left-hand helix — must be paired with a right-hand helical gear or matching left-hand rack for correct mesh.\u003c\/div\u003e\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003ch2\u003e✅ Key Features of These Left-Hand Helical Gears\u003c\/h2\u003e\n\u003cdiv class=\"hdiy-list\"\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e\u003cstrong\u003e304 Stainless Steel Construction\u003c\/strong\u003e\u003cp\u003eResists rust and oxidation in humid or mildly corrosive environments, extending service life over carbon steel alternatives.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\u003cstrong\u003e45° Left-Hand Helix Angle\u003c\/strong\u003e\u003cp\u003eEngineered 45-degree helix provides smoother tooth engagement, reduced operating noise, and improved load distribution compared to straight-cut spur gears.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🎯\u003c\/span\u003e\u003cstrong\u003eMultiple Tooth Counts: 13T \/ 15T \/ 20T\u003c\/strong\u003e\u003cp\u003eThree tooth count options across Module 1 and 1.5 allow flexible gear ratio selection for your specific speed and torque requirements.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔧\u003c\/span\u003e\u003cstrong\u003eWide Bore Range with Keyway Options\u003c\/strong\u003e\u003cp\u003ePlain bore from 6mm to 16mm, plus keyed bore variants (10mm+4mm keyway, 12mm+4mm, 14mm+5mm, 15mm+5mm) for positive shaft retention without set screws alone.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📏\u003c\/span\u003e\u003cstrong\u003eModule 1 \u0026amp; Module 1.5 Available\u003c\/strong\u003e\u003cp\u003eBoth metric module standards covered in one listing — select the module that matches your mating gear or rack for correct pitch compatibility.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🏭\u003c\/span\u003e\u003cstrong\u003eSuitable for CNC, Robotics \u0026amp; Automation\u003c\/strong\u003e\u003cp\u003eDimensionally consistent machining makes these gears a reliable drop-in for DIY CNC builds, robotic arms, conveyor drives, and custom motion control projects.\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 — Left-Hand Helical Gear\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003e304 Stainless Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eModule\u003c\/th\u003e\n\u003ctd\u003e1 \/ 1.5 (select variant)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHelix Angle\u003c\/th\u003e\n\u003ctd\u003e45°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHelix Direction\u003c\/th\u003e\n\u003ctd\u003eLeft-Hand\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTooth Count\u003c\/th\u003e\n\u003ctd\u003e13T \/ 15T \/ 20T (select variant)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore Diameter\u003c\/th\u003e\n\u003ctd\u003e6 \/ 8 \/ 10 \/ 12 \/ 14 \/ 15 \/ 16mm plain; keyed options available (select variant)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eKeyway\u003c\/th\u003e\n\u003ctd\u003e4mm (for 10–12mm bore) \/ 5mm (for 14–15mm bore) — See variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePitch Diameter (M1)\u003c\/th\u003e\n\u003ctd\u003eApprox. 13–20mm (0.51–0.79 in) depending on tooth count\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePitch Diameter (M1.5)\u003c\/th\u003e\n\u003ctd\u003eApprox. 15–30mm (0.59–1.18 in) depending on tooth count\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\u003eSurface Finish\u003c\/th\u003e\n\u003ctd\u003eMachined, natural stainless\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eApplication\u003c\/th\u003e\n\u003ctd\u003eCNC, robotics, automation, conveyor drives\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\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\u003csummary\u003eHow do I choose between Module 1 and Module 1.5?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eModule (M) defines the tooth size and pitch. Module 1 gears have smaller teeth and suit lighter loads or compact assemblies, while Module 1.5 gears have larger teeth and handle higher torque. You must match the module of your gear to the module of its mating gear or rack — mixing modules will result in incorrect mesh and damage.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eWhat does \"left-hand\" helix mean, and does it matter for my build?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eLeft-hand helix means the teeth spiral in a left-hand direction when viewed from the front. For parallel-shaft drives, a left-hand helical gear must mesh with a right-hand helical gear of the same helix angle and module. If you are replacing an existing gear, confirm the helix direction of the mating gear before ordering.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eWhich bore size should I select for my shaft?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eSelect a bore diameter that matches your shaft diameter exactly. For plain bore variants (6–16mm), the gear slides onto the shaft and is typically secured with a set screw or adhesive. For keyed variants, the keyway provides positive rotational locking — choose the keyway size that matches your shaft's key slot (4mm or 5mm).\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eIs 304 stainless steel strong enough for my application?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003e304 stainless steel offers good tensile strength (typically 515–620 MPa) and is well-suited for light-to-medium duty power transmission in CNC, robotics, and automation applications. For heavy industrial loads or high-impact environments, consider hardened steel or alloy steel gears instead. These gears are not rated for continuous high-torque industrial machinery.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eWill these gears corrode or rust?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003e304 stainless steel provides solid corrosion resistance in most indoor environments and light outdoor or humid conditions. It is not fully immune to corrosion in chloride-rich or highly acidic environments. For marine or chemical exposure, 316 stainless steel would be a more appropriate choice.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eCan I use these gears with a standard Module 1 or 1.5 rack?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThese are helical gears, not spur gears. A helical gear meshes with a helical rack of the same module and matching helix angle\/direction, or with another helical gear on a parallel shaft. They will not mesh correctly with a standard straight-tooth spur rack. Confirm your rack or mating gear is also helical with a 45° helix angle before purchasing.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eWhat is the difference between plain bore and keyed bore variants?\u003c\/summary\u003e\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003ePlain bore variants have a smooth cylindrical hole and rely on set screws or shaft collars for retention — easier to install but may slip under high torque. Keyed bore variants include a machined keyway slot that accepts a key inserted into a matching slot on the shaft, providing positive rotational locking and making them more suitable for higher-torque or reversing-load applications.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-cta\"\u003e\u003cp\u003e🛒 Select your Model (Module + Tooth Count) and Bore size above, then add to cart.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/div\u003e\u003cscript type=\"application\/ld+json\"\u003e{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"How do I choose between Module 1 and Module 1.5?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Module (M) defines the tooth size and pitch. Module 1 gears have smaller teeth and suit lighter loads or compact assemblies, while Module 1.5 gears have larger teeth and handle higher torque. You must match the module of your gear to the module of its mating gear or rack.\"}},{\"@type\":\"Question\",\"name\":\"What does left-hand helix mean, and does it matter for my build?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Left-hand helix means the teeth spiral in a left-hand direction when viewed from the front. For parallel-shaft drives, a left-hand helical gear must mesh with a right-hand helical gear of the same helix angle and module.\"}},{\"@type\":\"Question\",\"name\":\"Which bore size should I select for my shaft?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Select a bore diameter that matches your shaft diameter exactly. For plain bore variants, the gear is secured with a set screw. For keyed variants, the keyway provides positive rotational locking.\"}},{\"@type\":\"Question\",\"name\":\"Is 304 stainless steel strong enough for my application?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"304 stainless steel offers good tensile strength (typically 515-620 MPa) and is well-suited for light-to-medium duty power transmission in CNC, robotics, and automation applications.\"}},{\"@type\":\"Question\",\"name\":\"Will these gears corrode or rust?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"304 stainless steel provides solid corrosion resistance in most indoor environments and light outdoor or humid conditions. It is not fully immune to corrosion in chloride-rich or highly acidic environments.\"}},{\"@type\":\"Question\",\"name\":\"Can I use these gears with a standard Module 1 or 1.5 rack?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"These are helical gears and mesh with a helical rack of the same module and matching helix angle\/direction. They will not mesh correctly with a standard straight-tooth spur rack.\"}},{\"@type\":\"Question\",\"name\":\"What is the difference between plain bore and keyed bore variants?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Plain bore variants rely on set screws for retention. Keyed bore variants include a machined keyway slot for positive rotational locking, making them more suitable for higher-torque or reversing-load applications.\"}}]}\u003c\/script\u003e","brand":"HomeDIYer","offers":[{"title":"1M 13T \/ 6mm","offer_id":52439881548050,"sku":"GLFBQLPJGJXCD4242x1","price":27.99,"currency_code":"USD","in_stock":true},{"title":"1M 13T \/ 10mm","offer_id":52439881580818,"sku":"GLFBQLPJGJXCD4243x1","price":27.44,"currency_code":"USD","in_stock":true},{"title":"1M 15T \/ 6mm","offer_id":52439881613586,"sku":"GLFBQLPJGJXCD4244x1","price":30.6,"currency_code":"USD","in_stock":true},{"title":"1M 15T \/ 8mm","offer_id":52439881646354,"sku":"GLFBQLPJGJXCD4245x1","price":30.44,"currency_code":"USD","in_stock":true},{"title":"1M 15T \/ 10mm","offer_id":52439881679122,"sku":"GLFBQLPJGJXCD4246x1","price":30.16,"currency_code":"USD","in_stock":true},{"title":"1M 15T \/ 12mm","offer_id":52439881711890,"sku":"GLFBQLPJGJXCD4247x1","price":29.78,"currency_code":"USD","in_stock":true},{"title":"1M 20T \/ 10mm","offer_id":52439881744658,"sku":"GLFBQLPJGJXCD4248x1","price":38.87,"currency_code":"USD","in_stock":true},{"title":"1M 20T \/ 12mm","offer_id":52439881777426,"sku":"GLFBQLPJGJXCD4249x1","price":38.49,"currency_code":"USD","in_stock":true},{"title":"1M 20T \/ 14mm","offer_id":52439881810194,"sku":"GLFBQLPJGJXCD4250x1","price":37.94,"currency_code":"USD","in_stock":true},{"title":"1M 20T \/ 15mm","offer_id":52439881842962,"sku":"GLFBQLPJGJXCD4251x1","price":37.51,"currency_code":"USD","in_stock":true},{"title":"1M 20T \/ 16mm","offer_id":52439881875730,"sku":"GLFBQLPJGJXCD4252x1","price":37.24,"currency_code":"USD","in_stock":true},{"title":"1M 20T \/ Bore 10mm + Keyway 4mm","offer_id":52439881908498,"sku":"GLFBQLPJGJXCD4253x1","price":41.75,"currency_code":"USD","in_stock":true},{"title":"1M 20T \/ Bore 12mm + Keyway 4mm","offer_id":52439881941266,"sku":"GLFBQLPJGJXCD4254x1","price":41.32,"currency_code":"USD","in_stock":true},{"title":"1M 20T \/ Bore 14mm + Keyway 5mm","offer_id":52439881974034,"sku":"GLFBQLPJGJXCD4255x1","price":40.77,"currency_code":"USD","in_stock":true},{"title":"1M 20T \/ Bore 15mm + Keyway 5mm","offer_id":52439882006802,"sku":"GLFBQLPJGJXCD4256x1","price":40.39,"currency_code":"USD","in_stock":true},{"title":"1.5M 10T \/ 8mm","offer_id":52439882039570,"sku":"GLFBQLPJGJXCD4257x1","price":39.68,"currency_code":"USD","in_stock":true},{"title":"1.5M 10T \/ 10mm","offer_id":52439882072338,"sku":"GLFBQLPJGJXCD4258x1","price":39.41,"currency_code":"USD","in_stock":true},{"title":"1.5M 13T \/ Bore 10mm + Keyway 4mm","offer_id":52439882105106,"sku":"GLFBQLPJGJXCD4259x1","price":50.84,"currency_code":"USD","in_stock":true},{"title":"1.5M 13T \/ Bore 12mm + Keyway 4mm","offer_id":52439882137874,"sku":"GLFBQLPJGJXCD4260x1","price":50.46,"currency_code":"USD","in_stock":true},{"title":"1.5M 15T \/ Bore 10mm + Keyway 4mm","offer_id":52439882170642,"sku":"GLFBQLPJGJXCD4261x1","price":60.08,"currency_code":"USD","in_stock":true},{"title":"1.5M 15T \/ Bore 12mm + Keyway 4mm","offer_id":52439882203410,"sku":"GLFBQLPJGJXCD4262x1","price":59.54,"currency_code":"USD","in_stock":true},{"title":"1.5M 15T \/ Bore 14mm + Keyway 5mm","offer_id":52439882236178,"sku":"GLFBQLPJGJXCD4263x1","price":59.0,"currency_code":"USD","in_stock":true},{"title":"1.5M 15T \/ Bore 15mm + Keyway 5mm","offer_id":52439882268946,"sku":"GLFBQLPJGJXCD4264x1","price":58.72,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Main-04_f16b8c85-64f9-4850-9613-9904c62ebfdb.jpg?v=1783433893","url":"https:\/\/homediyer.com\/products\/module-1-1-5-helical-gear-304-stainless-steel-45-left-hand-13-15-20t-teeth","provider":"HomeDIYer","version":"1.0","type":"link"}