XL 10T-40T Timing Belt Pulley Synchronous Wheel for 10mm Width Belt,Select Bore

The tooth count determines your drive ratio. Divide the driven pulley tooth count by the driver pulley tooth count to get the ratio. For example, a 20T driver paired with a 10T driven pulley gives a 2:1 speed increase. Match your required linear speed or angular velocity to select the correct pairing. If you are replacing an existing pulley, count the teeth on the original or measure the pitch diameter.

A plain bore relies entirely on a set screw pressing against the shaft to transmit torque. A keyway bore has a machined slot that accepts a matching key on the shaft, creating a positive mechanical lock that prevents rotation under high or reversing loads. For high-torque or direction-reversing applications — such as CNC feed axes — a keyway bore is strongly recommended. For light-duty or low-torque uses like 3D printer carriages, a plain bore with a set screw is typically sufficient.

Yes, provided your belt is a standard XL-profile belt with 5.08 mm pitch and 10 mm width. The XL profile is an industry-standard designation, so these pulleys are compatible with XL belts from any manufacturer that conforms to the standard. If your belt is a different profile (T5, GT2, HTD, etc.) or a different width, these pulleys will not be compatible.

Use a digital caliper to measure the outer diameter of your shaft at the point where the pulley will be mounted. Select the bore size that matches your shaft diameter exactly — the bore is machined to a close tolerance. If your shaft has a keyway, also measure the keyway width and depth to confirm the keyway variant matches. Common shaft sizes include 5 mm, 6 mm, 8 mm, 10 mm, and 12 mm.

Yes. XL-series pulleys are widely used in desktop 3D printers (particularly for X/Y axis motion), small CNC routers, laser cutters, and similar maker equipment. The aluminum alloy construction keeps weight low while providing sufficient rigidity for the loads involved. Confirm that your machine uses XL-profile belts with 10 mm width before ordering — some machines use GT2 or T5 profiles instead.

Keyway variants are available with 3 mm, 4 mm, 5 mm, and 6 mm keyway widths, depending on the bore size selected. The correct keyway width is determined by the keyway already cut into your shaft — measure the width of the slot on your shaft with a caliper. As a general reference, 8 mm shafts commonly use a 3 mm keyway, 10 mm shafts use 3 mm or 4 mm, 12–14 mm shafts use 4–5 mm, and 15–20 mm shafts use 5–6 mm. Always verify against your specific shaft specification.

These pulleys are designed as drive pulleys mounted on a powered shaft. They can be used as idlers by mounting them on a bearing-supported shaft or bolt, but they do not include integrated bearings. If you need a bearing-mounted idler, you would need to press or slip-fit a bearing into the bore separately. Contact us to confirm bore tolerances if you plan to press-fit a bearing.