HTD-8M 10T-30T Timing Belts Pulley Pitch 8mm AF-type Drive Pulleys Width 21mm

The tooth count determines the pitch circle diameter and, combined with your belt length and the mating pulley's tooth count, sets your drive ratio. A smaller tooth count (e.g., 10T) gives a smaller pulley diameter — useful for compact, high-speed driver pulleys. A larger count (e.g., 30T) increases torque multiplication. Calculate your required ratio first, then select a tooth-count pair that fits your center distance and belt length.

Measure your motor or shaft diameter precisely with calipers. The AF-type hub is supplied with a pilot bore that can be finish-machined to your exact shaft size. Select the bore option closest to — but not smaller than — your shaft diameter if you plan to machine it yourself, or select the exact match if you need a ready-to-fit pulley. Available bores vary by tooth count; check the variant selector for options specific to your chosen tooth count.

Yes — these pulleys are designed to the standard HTD-8M tooth profile (8mm pitch, rounded HTD geometry) and are compatible with any HTD-8M timing belt of 21mm width. Ensure your belt width matches the 21mm pulley face. Using a narrower belt is possible but reduces torque capacity; a wider belt will not seat correctly.

The aluminum alloy construction and HTD tooth profile make these pulleys suitable for moderate-to-high torque synchronous drives typical of CNC machines, robotics, and light industrial equipment. The HTD profile spreads load across multiple teeth, reducing the risk of tooth jump under shock loads. For very high-torque or heavy-duty industrial applications, verify the torque rating against your system's peak load and consider steel pulleys if aluminum limits are exceeded.

The anodized aluminum surface provides good resistance to oxidation and mild chemical exposure typical of workshop environments (cutting fluids, light oils, humidity). Anodizing is not suitable for prolonged immersion in strong acids or alkalis. For outdoor or wet environments, inspect periodically and apply a light protective coating if needed.

Yes — the AF-type open hub is specifically designed to be machined after purchase. You can bore it to your exact shaft diameter, cut a keyway, or drill and tap set-screw holes using standard machine shop operations. This makes AF-type pulleys a popular choice when standard bore sizes don't match your shaft or when you need a keyed connection for high-torque transmission.

HTD (High Torque Drive) pulleys use a rounded, curvilinear tooth profile that provides a larger contact area between belt and pulley compared to the sharp trapezoidal profile of MXL/XL/L series. This results in lower tooth stress, reduced belt wear, and better performance under high-torque or shock-load conditions. HTD-8M is not interchangeable with trapezoidal-pitch belts — always match the belt and pulley to the same tooth profile and pitch.