HTD-5M 80T-120T Timing Belt Pulley Pitch 5mm With Keyway Drive Pulley Width 16mm

The tooth count determines the pitch diameter and, combined with your mating pulley's tooth count, sets your drive ratio. A higher tooth count gives a larger pulley diameter and a lower output speed (higher torque) for a given input speed. Calculate your required ratio first, then select the tooth count pair that achieves it within your available center distance.

Match the bore diameter to your motor or gearbox output shaft diameter. Common stepper motor shafts are 5–8mm, servo motors typically run 10–20mm, and larger BLDC or gearbox outputs may be 19–25mm. Always measure your shaft with calipers before ordering. The keyway dimensions are listed per variant — confirm they match your shaft's key specification.

Keyway dimensions are paired with bore size: 3×1.4mm (10mm bore), 4×1.8mm (10–12mm bore), 5×2.3mm (14–15mm bore), 6×2.8mm (19–20mm bore), and 8×3.3mm (25mm bore). These follow standard DIN 6885 key dimensions. Match the keyway width and depth to the key already cut on your shaft, or have a machinist cut a matching key slot.

Yes — these pulleys are designed for standard HTD-5M timing belts with a 5mm pitch and 16mm width. If your belt is a different width (e.g., 10mm or 20mm), the pulley face width will not match and you should select a pulley with the correct belt width instead.

The aluminum alloy construction is well-suited for light-to-medium torque synchronous drive applications such as CNC routers, 3D printer axes, and small robotic joints. For heavy industrial drives with sustained high torque or shock loads, a steel pulley may be more appropriate. The keyway and set-screw bore provide positive shaft engagement that prevents slippage under normal operating conditions.

Anodizing provides a hard oxide layer that significantly improves corrosion resistance compared to bare aluminum. These pulleys are suitable for indoor automation environments and light-duty outdoor use. For prolonged exposure to moisture, salt spray, or aggressive chemicals, additional protective measures or a stainless steel alternative should be considered.

Yes. The keyed bore makes it ideal as a driven or driving pulley on a shaft. It can also function as a guided idler if mounted on a bearing-supported shaft, though a flanged idler pulley without a keyway is typically preferred for pure idler applications to reduce unnecessary weight.