Timing Belt GT2 / HTD 5M / S5M / HTD 8M — Closed Loop Drive Belt, Width 6–30mm

Measure the center-to-center distance between your two pulleys, then use the standard belt length formula: Perimeter ≈ 2 × C + π × (D1 + D2) / 2, where D1 and D2 are the pulley pitch diameters. For example, a 2GT belt with 49 teeth has a perimeter of 98mm (≈3.86"). You can also simply count the teeth on your existing belt — the perimeter equals tooth count × pitch (e.g., 49 teeth × 2mm = 98mm for GT2). Always verify against your pulley tooth count before ordering.

GT2 has a 2mm pitch with a curvilinear tooth profile optimized for low backlash — the standard choice for 3D printer axis drives. HTD 5M uses a 5mm pitch with a rounded tooth designed for higher torque capacity in power transmission. S5M also uses a 5mm pitch but with a modified curvilinear profile for reduced backlash compared to HTD 5M — the two are not interchangeable despite the same pitch. HTD 8M has an 8mm pitch for heavy-duty industrial and robotics drives. Always match the profile to your existing pulleys.

Torque capacity depends on belt width, pitch, speed, and number of teeth in mesh. Generally, GT2 6mm belts are suited for light positioning loads (typically up to ~10 Nm), while HTD 8M 30mm belts can handle significantly higher torques (typically 50–150 Nm depending on speed and pulley size). For critical applications, apply a service factor of 1.5–2× to your calculated design load. Contact us if you need help sizing for a specific torque requirement.

These belts are generally made from neoprene rubber, which provides good resistance to moisture and moderate temperature ranges (typically –30°C to +80°C / –22°F to +176°F). They are not recommended for prolonged immersion in water or direct exposure to oils, fuels, or aggressive solvents without confirming chemical compatibility. For outdoor applications, protect the belt from direct UV exposure where possible. Contact us to confirm suitability for your specific environment.

No. While HTD 5M and S5M both use a 5mm pitch, their tooth profiles differ — HTD 5M uses a rounded (trapezoidal-derived) tooth, while S5M uses a modified curvilinear profile. Running an S5M belt on an HTD 5M pulley (or vice versa) will generally result in poor mesh, increased wear, and potential belt failure. GT2 pulleys (2mm pitch) are not compatible with any 5mm or 8mm belt. Always match belt profile and pitch to your pulley exactly.

Belt width should match your pulley flange width. Wider belts carry more load but require wider pulleys and more lateral clearance. As a general guide: 6mm is standard for GT2 in 3D printers; 10–15mm is common for light CNC and laser cutter gantries; 20–30mm is used for heavier industrial drives with HTD 5M, S5M, or HTD 8M profiles. If replacing an existing belt, measure the original belt width and match it exactly.

In most cases, yes — as long as you match the belt profile, pitch, perimeter, and width exactly to your machine's specification. For 3D printers (Ender, Prusa, Voron, etc.), GT2 6mm is typically the correct choice; check your machine's documentation for the exact perimeter. For CNC routers and laser cutters, confirm the belt profile and perimeter from your machine's BOM or by measuring the existing belt. If you are unsure, contact us with your machine model and we will help confirm compatibility.