Convex Spur Gear 2.0 Mod #45 Steel Convex Spur Gears 36T~50T Bore=14mm~30mm

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Convex Spur Gear 2.0 Mod #45 Steel Convex Spur Gears 36T~50T Bore=14mm~30mm

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By HomeDIYer®

Mod/Teeth: 2M-36T

Bore+Keyway: Burr hole

Price:

$114.95 USD

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In stock (500 units), ready to be shipped

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2.0 Mod #45 Steel Convex Spur Gears — Reliable Power Transmission for DIY Automation

When your motion-control build demands consistent torque transfer and tight mesh accuracy, an undersized or poorly machined spur gear becomes the weakest link in the entire drivetrain. Whether you are a maker assembling a CNC gantry, an engineer prototyping a conveyor stage, or a hobbyist building a custom gearbox, these 2.0 module convex spur gears are engineered to deliver repeatable, low-backlash performance across a wide range of shaft sizes.

Each gear is machined from #45 carbon steel — a medium-carbon alloy known for its balance of hardness, toughness, and machinability — and features a convex tooth profile that promotes smooth engagement and reduces edge loading under load. The tooth count range spans 36T to 50T, and bore options run from 14 mm (~0.55 in) up to 30 mm (~1.18 in), with keyway dimensions matched to each bore size per standard DIN/JIS conventions. A burr-hole (unfinished bore) option is also available for custom boring to your exact shaft diameter.

Typical use cases include DIY CNC router Z-axis drives, small-scale conveyor belt reduction stages, robotic arm joint assemblies, and educational lab gear-train demonstrations — anywhere a 2.0 mod pitch gear with a keyed bore is required for positive shaft engagement.

⚙️ Compatibility: Meshes with any standard 2.0 module (Mod 2) spur or helical gear. Verify center distance using the formula: CD = (T1 + T2) × m / 2, where m = 2.0 mm. Bore+Keyway dimensions follow standard DIN 6885 keyway tolerances.

✅ Key Features of These 2.0 Mod #45 Steel Convex Spur Gears

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#45 Carbon Steel Construction

Machined from #45 medium-carbon steel for a strong combination of surface hardness and core toughness, resisting wear under sustained rotational loads.

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Convex Tooth Profile

The convex tooth geometry promotes gradual tooth engagement, reducing impact noise and distributing contact stress more evenly across the face width compared to standard straight-cut profiles.

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Wide Tooth Count Range: 36T – 50T

Five tooth-count options (36T, 38T, 40T, 45T, 50T) let you dial in the exact gear ratio needed for your reduction stage without custom machining.

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Multiple Bore + Keyway Options

Bore sizes from 14 mm to 30 mm with matched keyways (K=5 to K=10 mm) ensure positive shaft locking. A burr-hole option is available for custom boring to your exact shaft diameter.

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Standard 2.0 Module Pitch

Fully interchangeable with any Mod 2 gear in your drivetrain — no special tooling or adapters required. Drop-in compatible with standard 2.0 module racks, pinions, and mating gears.

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Broad Application Range

Suited for CNC machines, conveyor drives, robotic joints, educational gear-train kits, and general-purpose power transmission projects requiring a keyed spur gear.

📐 Technical Specifications — 2.0 Mod Convex Spur Gear

Module (Mod)	2.0 mm
Material	#45 Carbon Steel
Tooth Profile	Convex (modified involute)
Pressure Angle	20°
Tooth Count Options	36T, 38T, 40T, 45T, 50T
Pitch Diameter Range	72 mm – 100 mm (2.83 in – 3.94 in)
Bore Diameter Range	14 mm – 30 mm (0.55 in – 1.18 in)
Keyway Width Range	5 mm – 10 mm (matched to bore per DIN 6885)
Face Width	See variant options
Hub Diameter	See variant options
Surface Finish	See variant options
Bore Type Options	Burr hole (unfinished) or finished bore with keyway
Gear Standard	Compatible with DIN / JIS Mod 2 systems
Quantity per Order	1 piece

❓ Frequently Asked Questions

How do I choose the right tooth count for my application?

Select your tooth counts based on the gear ratio you need: divide the driven gear teeth by the driver gear teeth to get the ratio. For example, pairing a 40T gear with a 20T pinion gives a 2:1 reduction. Use the center distance formula CD = (T1 + T2) × 1 mm (for Mod 2) to verify shaft spacing before ordering.

What bore size should I order if my shaft diameter is between listed options?

Order the "Burr hole" variant, which ships with an unfinished bore. You or a local machine shop can then bore and key it to your exact shaft diameter. This is the recommended approach for non-standard shaft sizes or tight-tolerance fits.

Are these gears compatible with standard Mod 2 racks and pinions?

Yes. These gears follow the standard 2.0 module pitch, so they mesh correctly with any Mod 2 spur gear, rack, or pinion that uses a 20° pressure angle. Always confirm the pressure angle of your mating gear before assembly.

How strong are #45 steel gears compared to aluminum or plastic alternatives?

#45 carbon steel offers significantly higher tensile strength (typically 600–800 MPa) compared to aluminum (~270 MPa) or engineering plastics (~80 MPa). This makes them suitable for moderate-to-high torque applications where aluminum or plastic gears would deform or wear prematurely.

Do these gears require any surface treatment or lubrication?

#45 steel is not inherently corrosion-resistant. For outdoor or humid environments, apply a light machine oil or grease to the tooth faces and bore. For long-term corrosion protection, consider having the gear zinc-plated or applying a rust-inhibiting coating after installation.

What keyway standard do these gears follow?

The keyway dimensions follow DIN 6885 / JIS B 1301 standard proportions, where keyway width and depth are matched to the bore diameter. For example, a 20 mm bore uses a 6 mm wide keyway (K=6), and a 30 mm bore uses an 8 mm wide keyway (K=8). Always verify keyway dimensions against your shaft key before assembly.

Can I use these gears in a CNC router or 3D printer build?

Yes. These Mod 2 steel spur gears are well-suited for CNC router axis drives, extruder gearboxes, and similar maker builds where a keyed steel gear is needed for positive shaft engagement and repeatable positioning. Confirm your existing gear module is 2.0 before ordering.

🛒 Select your Mod/Teeth and Bore+Keyway above, then add to cart.