5M Timing Belt Pulley 15T-25T Synchronous Wheel Sprocket For 10-25mm Width Belt

The tooth count determines your drive ratio. Pair a smaller pulley on the motor shaft with a larger pulley on the driven shaft to reduce speed and increase torque, or use equal tooth counts for a 1:1 ratio. For most desktop CNC and 3D printer builds, 20T is a common starting point. Calculate your steps-per-mm or velocity requirements first, then select the tooth count that achieves your target ratio.

The first number (8 mm) is the bore's circular diameter; the second number (7.5 mm) is the distance across the flat (the "D" cut). Your motor or drive shaft must have a matching flat ground to this dimension. Measure your shaft's outer diameter and flat-to-round distance before selecting a bore size to ensure a secure, slip-free fit.

Match the tooth width to your belt width. Using a pulley narrower than your belt causes edge loading and accelerated wear; using one wider wastes material but is generally acceptable. For 5M belts, common widths are 10 mm, 15 mm, 20 mm, and 25 mm — select the next size up from your belt width for full-face engagement.

Yes. The 5M pitch (5 mm tooth-to-tooth spacing) is an industry-standard profile. These pulleys will mesh correctly with any 5M open-ended or closed-loop synchronous belt regardless of brand, as long as the tooth profile matches (typically HTD 5M or MXL 5M — confirm your belt's profile before ordering).

Aluminum alloy pulleys offer an excellent strength-to-weight ratio for light-to-medium duty applications such as 3D printers, desktop CNC routers, and small robotic joints. For heavy industrial conveyor or high-torque applications with continuous shock loading, steel pulleys may be more appropriate. Check your system's torque and radial load requirements against the pulley's rated capacity.

Aluminum alloy naturally forms a thin oxide layer that provides moderate corrosion resistance. For consistently humid, wet, or mildly corrosive environments, an anodized finish adds additional protection. For harsh chemical or saltwater exposure, consider stainless steel alternatives or apply a protective coating after installation.

Yes — these pulleys are widely used with NEMA 17 and NEMA 23 stepper motors as well as small servo motors. Verify that your motor shaft diameter and flat dimension match one of the available D-bore options (5×4.5 mm through 12×11 mm). If your motor shaft is round without a flat, you will need to have a flat ground onto the shaft or use a set-screw style pulley instead.