{"product_id":"0-5-mod-brass-pinion-spur-gear-28-teeth-bore-4-8mm","title":"0.5 Mod Brass Pinion Spur Gear 28 Teeth Bore 4\/5\/6\/6.35\/7\/8mm Transmission Gear","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003e0.5 Mod Brass Pinion Spur Gear 28T — Reliable Transmission for Precision Mechanical Drives\u003c\/h2\u003e\n\u003cp\u003eWhen a mismatched or undersized pinion gear causes slippage, noise, or premature wear in your drive train, the entire mechanism suffers. Hobbyists, robotics engineers, and small-machine builders who need a dimensionally accurate, corrosion-resistant 0.5 module spur gear with 28 teeth will find this brass pinion gear a dependable solution for tight-tolerance assemblies.\u003c\/p\u003e\n\u003cp\u003eEach gear is machined from solid brass, offering a balance of machinability, low friction, and natural corrosion resistance without surface coatings. The module is 0.5 (Mod 0.5), tooth count is 28T, and bore options span 4 mm (0.157 in), 5 mm (0.197 in), 6 mm (0.236 in), 6.35 mm (0.250 in \/ 1\/4 in), 7 mm (0.276 in), and 8 mm (0.315 in). Outer diameter is approximately 14.5 mm (0.571 in) based on the standard formula OD = (T + 2) × m.\u003c\/p\u003e\n\u003cp\u003eTypical use cases include RC car and drone transmission stages requiring a compact 0.5 mod pinion gear, desktop CNC and 3D-printer extruder drives where a brass spur gear 28 teeth resists wear against plastic mating gears, and small robotic joint actuators where a lightweight metal pinion gear for robotics keeps inertia low while maintaining torque transfer accuracy.\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 Mod 0.5 spur, rack, or pinion gear. Verify bore diameter matches your shaft before ordering. Pressure angle: 20° (standard).\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003ch2\u003e✅ Key Features of These 0.5 Mod Brass Pinion Spur Gears\u003c\/h2\u003e\n\u003cdiv class=\"hdiy-list\"\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e\n\u003cstrong\u003eSolid Brass Construction\u003c\/strong\u003e\n\u003cp\u003eMachined from brass alloy for inherent corrosion resistance, smooth meshing, and compatibility with both metal and plastic mating gears without aggressive wear.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\n\u003cstrong\u003eStandard Mod 0.5 — 28 Teeth\u003c\/strong\u003e\n\u003cp\u003eConforms to the ISO\/DIN Mod 0.5 standard with 28 teeth and a 20° pressure angle, ensuring interchangeability with any compliant Mod 0.5 gear in your drivetrain.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🎯\u003c\/span\u003e\n\u003cstrong\u003eSix Bore Sizes Available\u003c\/strong\u003e\n\u003cp\u003eChoose from 4 \/ 5 \/ 6 \/ 6.35 \/ 7 \/ 8 mm bore diameters to match common motor shafts, including the 6.35 mm (1\/4 in) imperial size used in many North American motors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e⚖️\u003c\/span\u003e\n\u003cstrong\u003eCompact \u0026amp; Lightweight\u003c\/strong\u003e\n\u003cp\u003eWith an outer diameter of approximately 14.5 mm, this pinion gear fits into space-constrained assemblies such as micro-gearboxes, RC transmissions, and compact robotic joints.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📦\u003c\/span\u003e\n\u003cstrong\u003eFlexible Pack Quantities\u003c\/strong\u003e\n\u003cp\u003eAvailable in 1, 2, 5, or 10-piece packs so you can order a single replacement or stock spares for production runs and prototyping batches.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔄\u003c\/span\u003e\n\u003cstrong\u003eLow-Friction Meshing\u003c\/strong\u003e\n\u003cp\u003eBrass-on-brass or brass-on-plastic contact produces lower operating noise and reduced heat compared to steel pinions in lightly loaded, high-speed applications.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ch2\u003e📐 Technical Specifications — Mod 0.5 Brass Spur Gear\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eModule (Mod)\u003c\/th\u003e\n\u003ctd\u003e0.5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of Teeth\u003c\/th\u003e\n\u003ctd\u003e28T\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\u003eOuter Diameter (OD)\u003c\/th\u003e\n\u003ctd\u003eApprox. 14.5 mm (0.571 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore Diameter\u003c\/th\u003e\n\u003ctd\u003e4 \/ 5 \/ 6 \/ 6.35 \/ 7 \/ 8 mm (see variant options)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eBrass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFinish\u003c\/th\u003e\n\u003ctd\u003eNatural brass (uncoated)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHub \/ Face Width\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eGear Type\u003c\/th\u003e\n\u003ctd\u003eSpur (parallel axis)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eStandard\u003c\/th\u003e\n\u003ctd\u003eISO \/ DIN Mod 0.5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePack Quantity\u003c\/th\u003e\n\u003ctd\u003e1 \/ 2 \/ 5 \/ 10 PCS (see variant options)\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\u003cdetails\u003e\n\u003csummary\u003eHow do I choose the correct bore size for my motor shaft?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eMeasure your motor or drive shaft diameter with a caliper. Select the bore that matches exactly — for example, choose 6.35 mm if your shaft is a standard 1\/4-inch imperial shaft. A bore that is too large will cause runout and slippage; a bore that is too small cannot be pressed on without machining.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWill this gear mesh with my existing Mod 0.5 gears?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. Any gear marked Mod 0.5 (or Module 0.5) with a 20° pressure angle will mesh correctly with this 28T pinion, regardless of tooth count on the mating gear. Confirm the pressure angle of your existing gears before mixing gear sets from different manufacturers.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eIs brass strong enough for my application?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eBrass is well-suited for light-to-moderate load applications such as RC vehicles, small robots, instrumentation, and hobby CNC machines. For heavy industrial loads or high-impact environments, a steel gear would be more appropriate. Brass offers lower noise and better corrosion resistance than steel in most hobby and light-duty scenarios.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eDoes brass corrode or require lubrication?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eBrass is naturally corrosion-resistant and will not rust. For best longevity, apply a light machine oil or grease to the tooth faces, especially in continuous-duty or high-speed applications. This reduces friction heat and extends the service life of both this gear and its mating gear.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I use this gear with a plastic mating gear?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. Brass is commonly paired with POM (Delrin), nylon, or other engineering plastics. The softer plastic gear acts as the sacrificial wear component, protecting the brass pinion. This combination is widely used in 3D printer extruders, RC gearboxes, and small appliance drives.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do I secure the gear to the shaft — is a set screw included?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eRetention method depends on the specific variant. Many brass pinion gears of this type are secured with a set screw threaded into the hub. Check the product images for your selected bore size. If a set screw is not included or visible, the gear may be press-fit or require a separate retaining collar.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat is the outer diameter and pitch diameter of this gear?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eFor a Mod 0.5 gear with 28 teeth: Pitch Diameter (PD) = T × m = 28 × 0.5 = 14.0 mm. Outer Diameter (OD) = (T + 2) × m = 30 × 0.5 = 15.0 mm. Note: actual machined OD may vary slightly by ±0.1–0.2 mm depending on manufacturing tolerance.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-cta\"\u003e\n🛒 Select your bore size and pack 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 correct bore size for my motor shaft?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Measure your motor or drive shaft diameter with a caliper. Select the bore that matches exactly — for example, choose 6.35 mm if your shaft is a standard 1\/4-inch imperial shaft. A bore that is too large will cause runout and slippage; a bore that is too small cannot be pressed on without machining.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will this gear mesh with my existing Mod 0.5 gears?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. Any gear marked Mod 0.5 (or Module 0.5) with a 20° pressure angle will mesh correctly with this 28T pinion, regardless of tooth count on the mating gear. Confirm the pressure angle of your existing gears before mixing gear sets from different manufacturers.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is brass strong enough for my application?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Brass is well-suited for light-to-moderate load applications such as RC vehicles, small robots, instrumentation, and hobby CNC machines. For heavy industrial loads or high-impact environments, a steel gear would be more appropriate.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Does brass corrode or require lubrication?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Brass is naturally corrosion-resistant and will not rust. For best longevity, apply a light machine oil or grease to the tooth faces, especially in continuous-duty or high-speed applications.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I use this gear with a plastic mating gear?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. Brass is commonly paired with POM (Delrin), nylon, or other engineering plastics. The softer plastic gear acts as the sacrificial wear component, protecting the brass pinion.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How do I secure the gear to the shaft — is a set screw included?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Retention method depends on the specific variant. Many brass pinion gears of this type are secured with a set screw threaded into the hub. Check the product images for your selected bore size.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the outer diameter and pitch diameter of this gear?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"For a Mod 0.5 gear with 28 teeth: Pitch Diameter (PD) = 28 × 0.5 = 14.0 mm. Outer Diameter (OD) = (28 + 2) × 0.5 = 15.0 mm. Actual machined OD may vary by ±0.1–0.2 mm.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"HomeDIYer","offers":[{"title":"0.5 Mod 28T 【Bore 4mm】 \/ 1 PCS","offer_id":52442805436690,"sku":"AdaahGFCD04389x1","price":8.64,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 5mm】 \/ 1 PCS","offer_id":52442805469458,"sku":"AdaahGFCD04390x1","price":8.64,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 6mm】 \/ 1 PCS","offer_id":52442805502226,"sku":"AdaahGFCD04391x1","price":8.64,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 6.35mm】 \/ 1 PCS","offer_id":52442805534994,"sku":"AdaahGFCD04392x1","price":8.74,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 7mm】 \/ 1 PCS","offer_id":52442805567762,"sku":"AdaahGFCD04393x1","price":8.74,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 8mm】 \/ 1 PCS","offer_id":52442805600530,"sku":"AdaahGFCD04394x1","price":8.74,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 4mm】 \/ 2 PCS","offer_id":52442805633298,"sku":"AdaahGFCD04389x2","price":13.55,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 5mm】 \/ 2 PCS","offer_id":52442805666066,"sku":"AdaahGFCD04390x2","price":13.55,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 6mm】 \/ 2 PCS","offer_id":52442805698834,"sku":"AdaahGFCD04391x2","price":13.55,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 6.35mm】 \/ 2 PCS","offer_id":52442805731602,"sku":"AdaahGFCD04392x2","price":14.09,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 7mm】 \/ 2 PCS","offer_id":52442805764370,"sku":"AdaahGFCD04393x2","price":14.09,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 8mm】 \/ 2 PCS","offer_id":52442805797138,"sku":"AdaahGFCD04394x2","price":14.09,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 4mm】 \/ 5 PCS","offer_id":52442805829906,"sku":"AdaahGFCD04389x5","price":25.13,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 5mm】 \/ 5 PCS","offer_id":52442805862674,"sku":"AdaahGFCD04390x5","price":25.08,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 6mm】 \/ 5 PCS","offer_id":52442805895442,"sku":"AdaahGFCD04391x5","price":25.0,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 6.35mm】 \/ 5 PCS","offer_id":52442805928210,"sku":"AdaahGFCD04392x5","price":27.64,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 7mm】 \/ 5 PCS","offer_id":52442805960978,"sku":"AdaahGFCD04393x5","price":27.49,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 8mm】 \/ 5 PCS","offer_id":52442805993746,"sku":"AdaahGFCD04394x5","price":27.3,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 4mm】 \/ 10 PCS","offer_id":52442806026514,"sku":"AdaahGFCD04389x10","price":45.36,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 5mm】 \/ 10 PCS","offer_id":52442806059282,"sku":"AdaahGFCD04390x10","price":45.22,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 6mm】 \/ 10 PCS","offer_id":52442806092050,"sku":"AdaahGFCD04391x10","price":45.0,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 6.35mm】 \/ 10 PCS","offer_id":52442806124818,"sku":"AdaahGFCD04392x10","price":50.03,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 7mm】 \/ 10 PCS","offer_id":52442806157586,"sku":"AdaahGFCD04393x10","price":49.76,"currency_code":"USD","in_stock":true},{"title":"0.5 Mod 28T 【Bore 8mm】 \/ 10 PCS","offer_id":52442806190354,"sku":"AdaahGFCD04394x10","price":49.3,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture4of13_3c7cadbf-8665-4829-8c2d-ba2ac826d68e.jpg?v=1783602799","url":"https:\/\/homediyer.com\/products\/0-5-mod-brass-pinion-spur-gear-28-teeth-bore-4-8mm","provider":"HomeDIYer","version":"1.0","type":"link"}