5M AF-Type Timing Belt Pulley 22/24T Synchronous Wheel For 15mm/20mm Width Belt

The tooth count determines the pitch diameter and, combined with your motor's RPM, the linear speed of your belt drive. A 22T pulley has a slightly smaller pitch diameter (~35.0 mm) and produces a lower linear speed per revolution than a 24T (~38.2 mm). If you are replacing an existing pulley, match the tooth count exactly. If you are designing a new system, choose based on your target speed-to-torque ratio — more teeth means a larger diameter and slightly more torque leverage at the same belt tension.

A round bore is a plain cylindrical hole that is typically secured with a set screw against the shaft. A D-bore (flat-cut bore) has one or more flat faces machined into the bore wall that match a corresponding flat on a D-shaft motor output. D-bore variants provide a positive mechanical key without relying solely on set-screw friction, which is especially useful on stepper motors where shaft slippage under reversing loads can cause positional errors. Check your motor's shaft profile before selecting a variant.

Yes — these pulleys are machined to the standard 5M synchronous tooth profile (5 mm pitch, matching tooth geometry). They are compatible with any standard 5M open-ended or closed-loop timing belt. Ensure you also select the correct belt width variant (15 mm or 20 mm) to match your belt's width, as the flange spacing is sized accordingly.

Aluminum alloy offers natural oxidation resistance suitable for indoor automation environments — CNC workshops, 3D printer enclosures, and light industrial settings. The natural aluminum finish does not include an anodized or coated layer, so in high-humidity or outdoor environments, a light application of dry lubricant or corrosion inhibitor is advisable. For harsh chemical or marine environments, consider stainless steel pulleys instead.

No — the flange spacing on each pulley variant is sized to match the specified belt width. Using a 15 mm pulley with a 20 mm belt will cause the belt to overhang the flanges and risk derailment. Always match the pulley's belt-width specification to your belt's actual width. If you are upgrading from a 15 mm to a 20 mm belt for higher torque capacity, you must also replace the pulley with the 20 mm variant.

The most common NEMA 17 stepper motor shaft is 5 mm round, but this product starts at 6 mm bore — check your motor's datasheet for the exact shaft diameter. NEMA 23 motors typically use 6.35 mm (1/4 in) or 8 mm shafts. Servo motors and larger steppers may use 10 mm, 12 mm, or larger shafts. If your motor has a D-shaft (flat-cut), select the corresponding D-bore variant (e.g., 8 mm 3×1.4 mm flat for an 8 mm D-shaft). When in doubt, measure the shaft diameter with calipers before ordering.

Set screw inclusion varies by variant. Round-bore pulleys typically include a set screw in the hub for shaft retention. D-bore variants rely on the flat engagement for primary retention and may or may not include a set screw. Please refer to the product images or contact us to confirm set screw inclusion for your specific variant before ordering.