BF-type HTD8M 25mm-30mm Timing Belt Pulley 12 - 72 Tooth for CNC Step Motor

The tooth count determines the pitch diameter and, combined with your motor pulley tooth count, sets the speed/torque ratio of your belt drive. Divide the driven pulley teeth by the drive pulley teeth to get the reduction ratio. For CNC routers and laser engravers, common pairings are 20 T drive / 40 T driven (2:1 reduction) or matched tooth counts for 1:1 direct drive. Select the tooth count that achieves your target ratio without exceeding your available center distance.

The belt width affects torque capacity and lateral stability. A 30 mm wide pulley and belt can transmit more torque than a 25 mm set at the same speed, making it better suited for heavier gantry axes or high-acceleration servo systems. The 25 mm variant is a good fit for lighter loads, compact builds, or where frame clearance is limited. Both variants use the same HTD 8M tooth pitch — only the width differs.

The BF-type hub uses a through-bore secured by a set screw against a machined flat. Bore diameter varies by tooth count. Please check the bore specification for your selected variant or contact us to confirm compatibility with your motor shaft diameter (common sizes include 6.35 mm, 8 mm, 10 mm, 12 mm, and 14 mm). If your shaft diameter is not listed, reach out before ordering.

Yes. These pulleys are machined to the HTD 8M tooth profile standard (8 mm pitch, rounded tooth form). They are compatible with any HTD 8M open-end or closed-loop timing belt of matching width (25 mm or 30 mm). They are not compatible with GT2, T5, T10, or other pitch belts — always verify the belt pitch before ordering.

The BF-type hub set screw bears against a flat ground onto the shaft, which prevents rotation and axial movement under normal operating loads. For high-shock or reversing-load applications, consider using a thread-locking compound on the set screw and verifying the screw torque specification. For very high torque applications, a keyed bore variant may be more appropriate — contact us if you need guidance.

Yes — HTD 8M pulleys are widely used in CNC router X/Y/Z axes and laser engraver gantry systems where the 8 mm pitch provides a good balance of tooth strength and positional resolution. Pair with an HTD 8M belt of matching width and ensure your idler or tensioner is also rated for 8M pitch. The 25 mm width is common for lighter laser gantries; the 30 mm width suits heavier CNC router axes.

Center distance depends on the pitch diameters of both pulleys and the belt length. Use the formula: C ≈ (L − π × (D1 + D2) / 2) / 2, where L is the belt length and D1/D2 are the pitch diameters of the two pulleys. Many free online belt-drive calculators accept tooth count and pitch as inputs and will output the required center distance for a given belt length. Always allow for a small amount of tensioner adjustment range in your design.