Buying guide

How to Choose a Timing Pulley: Teeth, Bore and Width

Four checks before you order a GT2 or HTD pulley.

1. Profile and pitch. It must match the belt, for example GT2 pulley with GT2 belt.
2. Tooth count. More teeth means more travel per motor revolution and a larger belt wrap. For GT2, travel per revolution = teeth × 2 mm, so a 20-tooth pulley moves the belt 40 mm per turn.
3. Bore. Match the shaft: common stepper motor shafts are 5 mm, 6.35 mm and 8 mm. Ask for a custom bore if yours is different.
4. Belt width. The pulley must be at least as wide as the belt. A 6 mm belt uses a 6 mm pulley.

Pulleys come with set-screw or clamp fixing, in aluminum or steel. Idler pulleys, toothed or smooth, are listed separately. Browse timing pulleys.