Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
When 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.
Each 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.
Typical 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.
Machined from brass alloy for inherent corrosion resistance, smooth meshing, and compatibility with both metal and plastic mating gears without aggressive wear.
Conforms 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.
Choose 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.
With 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.
Available in 1, 2, 5, or 10-piece packs so you can order a single replacement or stock spares for production runs and prototyping batches.
Brass-on-brass or brass-on-plastic contact produces lower operating noise and reduced heat compared to steel pinions in lightly loaded, high-speed applications.
| Module (Mod) | 0.5 |
|---|---|
| Number of Teeth | 28T |
| Pressure Angle | 20° |
| Outer Diameter (OD) | Approx. 14.5 mm (0.571 in) |
| Bore Diameter | 4 / 5 / 6 / 6.35 / 7 / 8 mm (see variant options) |
| Material | Brass |
| Finish | Natural brass (uncoated) |
| Hub / Face Width | See variant options |
| Gear Type | Spur (parallel axis) |
| Standard | ISO / DIN Mod 0.5 |
| Pack Quantity | 1 / 2 / 5 / 10 PCS (see variant options) |
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.
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.
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. Brass offers lower noise and better corrosion resistance than steel in most hobby and light-duty scenarios.
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. This reduces friction heat and extends the service life of both this gear and its mating gear.
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. This combination is widely used in 3D printer extruders, RC gearboxes, and small appliance drives.
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. If a set screw is not included or visible, the gear may be press-fit or require a separate retaining collar.
For 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.
