HTD-5M 46T-60T Timing Belt Pulley With Expansion/Tension Sleeve Teeth Width 21mm

The tooth count determines the pulley's pitch circumference (46T = 230 mm, 48T = 240 mm, 50T = 250 mm, 60T = 300 mm). Choose based on your required gear ratio and the center distance between your drive and driven shafts. A larger tooth count on the driven pulley relative to the drive pulley reduces output speed and increases torque. Use a belt-length calculator to confirm your belt length once you've selected both pulleys.

The expansion sleeve bore is available in 21 sizes: 5, 6, 6.35, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 20, 22, 24, 25, 28, 30, and 32 mm. Select the option that matches your motor or gearbox shaft diameter exactly. The 6.35 mm option suits ¼-inch imperial shafts common on North American motors.

The expansion (tension) sleeve is a split collet-style insert that compresses uniformly around the shaft when the clamping bolt is tightened. This distributes clamping force over a larger contact area than a single set screw, reducing the risk of shaft marring and providing more consistent torque transmission. It also allows the pulley to be repositioned angularly without removing it from the shaft, which is useful during belt-tension adjustment.

Yes. The tooth profile follows the HTD-5M standard (5 mm pitch, curvilinear tooth form). It is compatible with any HTD-5M synchronous belt with a 20 mm or 21 mm width. It is not compatible with GT2, MXL, XL, or other pitch belts — always verify the belt pitch before ordering.

Aluminum alloy offers a good balance of light weight and corrosion resistance for typical indoor workshop conditions. The natural oxide layer that forms on aluminum provides adequate protection against humidity and mild chemical exposure. For outdoor or high-moisture environments, consider applying a light coating of dry lubricant to the bore area. The tooth flanks are designed to run against rubber/polyurethane HTD belts and will not corrode under normal use.

Yes. NEMA 17 stepper motors typically have a 5 mm shaft — select the 5 mm bore option. NEMA 23 motors commonly use 6.35 mm (¼ in) or 8 mm shafts — select the matching bore. The expansion sleeve provides a secure, backlash-free connection without requiring a flat on the shaft, though a flat or keyway will further increase torque capacity.

Exact torque ratings depend on the specific bore size, clamping bolt torque, and shaft surface finish. As a conservative guideline for aluminum HTD-5M pulleys of this size, continuous transmitted torque is typically in the range of 5–20 N·m depending on bore diameter and clamping conditions. For high-torque applications, contact us to confirm suitability before ordering.