0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
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0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel

0.5 Mod 40T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel

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Price:
$4.34 USD
Stock:
In stock (500 units), ready to be shipped

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Description

0.5 Mod 40T Steel Spur Gears — Reliable Pinion Transmission for DIY Drive Systems

When your motion-control build demands consistent torque transfer and tight mesh tolerances, undersized or poorly finished gears become the weakest link. Makers, robotics enthusiasts, and small-shop engineers working on CNC machines, 3D printer extruder drives, and RC drivetrains need a spur gear that holds its tooth profile under load — these 0.5 Module 40-tooth steel pinion gears are machined for exactly that purpose.

Each gear is cut from 45# carbon steel, offering a tensile strength typically in the 600–800 MPa range, with a hardness of approximately HRC 20–30 in the as-machined state. The module is 0.5 (pitch diameter = 20 mm / 0.79 in), tooth count is 40T, and bore options span 5 mm, 6 mm, 6.35 mm (1/4 in), 8 mm, and 10 mm to suit a wide range of shaft diameters. Teeth height is available in 3 mm and 5 mm variants. Quantity packs range from 1 to 50 pieces per order.

Typical use cases include: compact robotic joint drives requiring a 0.5 mod gear mesh with a mating pinion; CNC router Z-axis rack-and-pinion systems where a steel spur gear outperforms plastic alternatives; and DIY motorized camera slider or conveyor builds that need repeatable, low-backlash power transmission across a 40-tooth steel spur gear stage.

⚙️ Compatibility: Meshes with any 0.5 Module (Mod 0.5) spur or rack gear. Bore sizes 5 mm, 6 mm, 6.35 mm, 8 mm, and 10 mm — confirm your shaft diameter before ordering. Teeth height 3 mm or 5 mm — select to match your mating gear face width.

✅ Key Features of These 0.5 Mod 40T Steel Spur Gears

🔩 45# Carbon Steel Construction

Machined from 45# carbon steel for solid tooth strength and wear resistance in continuous-duty drive applications.

📐 0.5 Module, 40 Teeth

Standard Mod 0.5 tooth profile ensures direct mesh compatibility with any 0.5 mod rack, pinion, or mating spur gear in your drivetrain.

🎯 Multiple Bore Options

Available in 5 mm, 6 mm, 6.35 mm (1/4"), 8 mm, and 10 mm bore diameters to fit common motor and shaft sizes without custom machining.

📏 Two Teeth Height Variants

Choose 3 mm or 5 mm teeth height to match your mating gear face width and optimize load distribution across the tooth contact zone.

📦 Flexible Pack Quantities

Order 1, 5, 10, 15, 20, 30, or 50 pieces — scale your purchase to prototype quantities or full production runs without overstocking.

🔄 Broad Application Range

Suited for robotics joints, CNC axis drives, extruder gearboxes, motorized sliders, and any compact power-transmission stage requiring a steel spur gear.

📐 Technical Specifications — 0.5 Mod Spur Gears

Module 0.5
Tooth Count 40T
Pitch Diameter 20 mm (0.79 in)
Teeth Height 3 mm or 5 mm (see variant options)
Bore Diameter 5 mm / 6 mm / 6.35 mm / 8 mm / 10 mm (see variant options)
Material 45# Carbon Steel
Pressure Angle 20°
Gear Type External Spur Gear
Surface Finish See variant options
Pack Quantity 1 / 5 / 10 / 15 / 20 / 30 / 50 pcs (see variant options)

❓ Frequently Asked Questions

How do I choose between the 3 mm and 5 mm teeth height options?

Match the teeth height to the face width of your mating gear. A 5 mm face width provides a larger contact area and distributes load more evenly, making it better for higher-torque applications. The 3 mm variant is suited for compact builds where axial space is limited and torque demands are moderate.

Which bore size should I select for my motor shaft?

Measure your motor or drive shaft diameter precisely before ordering. Available bores are 5 mm, 6 mm, 6.35 mm (standard 1/4" imperial shaft), 8 mm, and 10 mm. If your shaft is slightly undersized, a set screw or keyway can be used to secure the gear — confirm your shaft spec first.

Will this gear mesh with my existing 0.5 mod rack or pinion?

Yes. Any gear or rack with a 0.5 Module (Mod 0.5) and a standard 20° pressure angle will mesh correctly with these 40T spur gears. Verify the module and pressure angle of your mating component before assembly.

How strong is 45# carbon steel compared to other gear materials?

45# carbon steel offers a tensile strength typically in the 600–800 MPa range and is significantly stronger than nylon, acetal (POM), or aluminum gears of the same size. It is well-suited for continuous-duty drives. For very high-cycle or high-impact applications, consider whether a heat-treated or alloy steel variant would better suit your load requirements.

Are these gears corrosion-resistant?

45# carbon steel has moderate corrosion resistance. For indoor or dry environments, the as-machined surface is generally adequate. For humid, outdoor, or washdown environments, apply a light machine oil or consider a zinc-plated or stainless steel alternative to prevent surface oxidation.

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

Yes. The 0.5 Mod 40T profile is commonly used in compact CNC axis drives and extruder gearbox stages. Confirm that your mating gear or rack is also Mod 0.5, and select the bore size that matches your stepper motor or servo shaft diameter for a secure fit.

How many pieces do I need to order, and can I mix bore sizes?

Each variant listing is for a single bore size and teeth height combination. Select the specific variant (teeth height + bore + quantity) that matches your build. If you need multiple bore sizes, add each variant separately to your cart.

🛒 Select your Teeth Height, Bore size, and Qty above, then add to cart.

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