0.5 Mod 42T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
0.5 Mod 42T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
0.5 Mod 42T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
0.5 Mod 42T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
0.5 Mod 42T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel
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0.5 Mod 42T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel0.5 Mod 42T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel0.5 Mod 42T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel0.5 Mod 42T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel0.5 Mod 42T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel

0.5 Mod 42T Spur Gears Steel Pinion Gears Metal Spur Transmission Gear 45 Steel

HomeDIYer
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By HomeDIYer®

Price:
$4.58 USD
Stock:
In stock (500 units), ready to be shipped

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Description

0.5 Mod 42T Steel Spur Gears — Reliable Pinion Gear for Precision Transmission

When a stripped or undersized gear brings your build to a halt, you need a replacement that fits right the first time. These 0.5 module 42-tooth steel spur gears are designed for makers, robotics builders, RC hobbyists, and small-machine engineers who demand consistent mesh accuracy and long service life from every drivetrain component.

Each gear is machined from 45# carbon steel, delivering a tensile strength typically in the 600–800 MPa range with good wear resistance. The module is 0.5 (pitch diameter = 21 mm / ~0.827 in), tooth count is 42T, and bore options span 6 mm, 8 mm, and 10 mm to suit a range of shaft diameters. Face width is typically 5–8 mm (~0.20–0.31 in) depending on the variant.

Typical use cases include DC gearmotor output stages in desktop CNC machines, servo-driven steering racks in 1/10-scale RC vehicles, and compact conveyor or indexing mechanisms in DIY automation projects — anywhere a low-module spur gear for small shaft drives is required.

⚙️ Compatibility: Meshes with any 0.5-module spur or pinion gear. Bore sizes 6 mm, 8 mm, and 10 mm suit standard motor and gearbox output shafts. Confirm shaft diameter and keyway requirements before ordering.

✅ Key Features of These 0.5 Mod 42T Steel Spur Gears

🔩45# Carbon Steel Construction
Machined from 45# carbon steel for solid load-bearing capacity and resistance to tooth deformation under cyclic stress — a dependable choice for continuous-duty transmission applications.
📐0.5 Module, 42-Tooth Profile
Standard 0.5 mod tooth geometry ensures accurate mesh with any compatible 0.5-module gear, minimising backlash and noise in precision motion systems.
🎯Three Bore Options: 6 / 8 / 10 mm
Select the bore that matches your motor or gearbox shaft — 6 mm, 8 mm, or 10 mm — for a direct, secure fit without additional machining in most standard applications.
📦Flexible Pack Quantities (1–50 pcs)
Order a single gear for a one-off repair or up to 50 pieces for production runs and spares inventory, with per-unit cost decreasing at higher quantities.
🔄Consistent Tooth Accuracy
Gears are produced to repeatable dimensional tolerances, supporting smooth, low-vibration power transfer in robotics, RC drivetrains, and compact automation equipment.
🛠️Broad DIY & Maker Compatibility
Suited for desktop CNC builds, servo-driven RC steering, small conveyor indexers, and any project requiring a compact 0.5-module spur gear for small shaft drives.

📐 Technical Specifications — 0.5 Mod Spur Gears

Module 0.5
Number of Teeth 42T
Pitch Diameter 21 mm (~0.827 in)
Bore Diameter 6 mm / 8 mm / 10 mm (see variant options)
Face Width See variant options
Material 45# Carbon Steel
Pressure Angle 20° (standard)
Gear Type Spur Gear (external)
Finish See variant options
Pack Quantity 1 / 5 / 10 / 15 / 20 / 30 / 40 / 50 pcs

❓ Frequently Asked Questions

How do I choose the right bore size for my motor shaft?

Measure your motor or gearbox output shaft diameter with a caliper. Select the 6 mm bore for shafts up to 6 mm, 8 mm for shafts up to 8 mm, and 10 mm for shafts up to 10 mm. If your shaft uses a keyway or set-screw flat, confirm the gear hub depth is sufficient before ordering.

Will this gear mesh with my existing 0.5-module gears?

Yes. Any gear with a 0.5 module and a 20° pressure angle will mesh correctly with these 42T gears. Module and pressure angle must match between mating gears — tooth count only affects the gear ratio, not compatibility.

How strong are these gears under load?

45# carbon steel typically achieves a tensile strength of 600–800 MPa after standard heat treatment, making it suitable for moderate-load continuous-duty applications such as RC drivetrains, small servo mechanisms, and desktop automation. For very high-torque or shock-load environments, consider a larger module gear.

Are these gears corrosion-resistant?

45# carbon steel has moderate corrosion resistance. For indoor or dry environments these gears perform well with light lubrication. For humid or outdoor use, apply a suitable gear grease or consider a stainless-steel alternative to extend service life.

What gear ratio can I achieve with a 42T spur gear?

Gear ratio is determined by pairing this 42T gear with a pinion of a different tooth count. For example, pairing with a 14T pinion gives a 3:1 reduction ratio. Pair with any 0.5-module gear of your chosen tooth count to achieve the ratio your application requires.

How many pieces should I order for a project?

For a single-axis build or repair, 1 pc is sufficient. For multi-axis machines or production runs, ordering 10–50 pcs reduces per-unit cost and ensures you have spares on hand. The quantity selector above shows the price per pack so you can compare before adding to cart.

Do these gears require lubrication?

Yes, light lubrication is recommended for all steel spur gears to reduce wear and noise. Apply a thin film of gear grease or light machine oil to the tooth faces during installation and re-lubricate periodically based on duty cycle and operating speed.

🛒 Select your Teeth–Bore size and quantity above, then add to cart.

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