Ordering a replacement timing belt sounds simple until you face a code like "8M-1200-25". Once you know what each part means, you can identify almost any synchronous belt in a minute.
1. Profile. The profile is the tooth shape. Common families include trapezoidal profiles (such as MXL, XL, L and H) and curvilinear profiles (such as HTD and GT types). Profiles are not interchangeable. A belt only runs properly on a pulley made for the same profile.
2. Pitch. Pitch is the distance between the centers of two adjacent teeth. In "8M", the 8 usually means an 8 mm pitch. A larger pitch generally carries more load, while a smaller pitch suits compact, precise drives.
3. Length. Length is often given as the pitch length in millimeters. A useful check is that pitch length equals pitch multiplied by the number of teeth. A 1200 mm belt with an 8 mm pitch has 150 teeth.
4. Width. Width is the belt's face width, and it strongly affects load capacity. The last number in many codes gives it in millimeters.
5. Material. Rubber timing belts are widely used across industry. Polyurethane belts are often chosen for wear resistance and clean running. Your operating environment (temperature, oil, dust, washdown) should guide this choice.
Before you order, measure these:
- Number of teeth and pitch on the old belt
- Belt width
- Pulley tooth count and center distance
- Any wear or damage that hints at a wrong specification
If the old belt is unreadable, a pulley or a photo of the drive can be enough for an experienced engineer to identify the profile.
Browse the range of rubber timing belts, polyurethane timing belts and matching timing pulleys. Not sure what you have? Contact the KUEISN team with your drawings or samples.