Steel or Aluminum – Choosing the Right Koswork Motor Pinion Gear for Your 5mm Shaft
Pinion gear choice comes down to two things: how much wear you need it to take, and how much weight you’re willing to trade off for it. Koswork covers both with two lines built for 5mm shaft motors: the KOS03006 Mod 1 Lightweight Hardened Steel Pinion Gear in 13T through 18T, and the KOS03009 Mod 1 7075 Aluminum Pinion Gear in 15T through 17T.
KOS03006 Hardened Steel – Built for 5mm Bore Motors
The KOS03006 is made from hardened steel material and lightened for best acceleration. It’s built for 5mm bore motors and uses a large 5mm set screw that grips better than smaller sizes. Every piece is precisely CNC machined, lightened, and hardened, and it’s available in six tooth counts — 13T, 14T, 15T, 16T, 17T, and 18T.
KOS03009 Aluminum – Lightweight with Faster Rotation
The KOS03009 is machined from 7075 aluminum with a hardened treatment. Its lightweight design is built for great acceleration and faster rotation — the 15T version weighs just 3 grams. It’s made specifically for 5mm motor shafts, with a large 5mm flathead set screw to prevent stripping, and precision CNC machining for high accuracy. It comes in 15T, 16T, and 17T. Note: use with plastic spur gears only.
Between the two, it comes down to what you need from your drivetrain. Steel if you want a pinion built to take wear over the long run. Aluminum if you’re chasing lighter rotating weight and your car runs a plastic spur gear. Made in Taiwan, cars, parts, and accessories not included.
