H-Type Rubber Timing Belt 12.7mm Pitch – Closed Loop Synchronous Belt, 25mm & 30mm Wide

The H-series length designation refers to the pitch length in tenths of an inch. For example, 200H = 20.0 inches (≈508mm) total belt circumference. To select the correct length, measure your center-to-center pulley distance and calculate the required belt loop circumference using standard belt length formulas. When in doubt, size up to the next available length to allow for tensioner adjustment.

'H' refers to the H-series tooth profile standard, which specifies a 12.7mm (1/2 inch) pitch — the distance between adjacent tooth centers. This is a widely used industrial standard for moderate-to-high torque synchronous drive applications. It is not interchangeable with other pitch standards such as L (9.525mm) or XH (22.225mm).

H-type rubber timing belts generally handle moderate-to-high torque loads in synchronous drive systems. Actual capacity depends on belt width, length, pulley diameter, speed, and service conditions. Wider belts (30mm) typically carry more load than narrower ones (25mm). For precise torque ratings, consult your drive system specifications or contact us to confirm.

These rubber synchronous belts are generally resistant to light moisture and dust under normal operating conditions. However, prolonged exposure to oils, solvents, fuels, or extreme UV radiation may degrade the rubber compound over time. For harsh outdoor, chemical, or high-humidity environments, contact us to confirm suitability before ordering.

These belts are compatible with standard H-series timing pulleys with a 12.7mm (1/2 inch) pitch tooth profile. Ensure your pulley groove profile matches the H-tooth trapezoidal shape. Both 25mm and 30mm wide belts require pulleys with a face width equal to or greater than the belt width. Mixing different pitch standards will result in poor meshing and premature wear.

Choose 25mm width for lighter-duty or space-constrained applications where a narrower belt profile is needed. Select 30mm width when higher torque capacity, greater lateral stability, or a wider pulley face is specified. In most cases, the belt width should match the pulley face width as closely as possible — generally within ±2mm.

The pitch is 12.7mm (1/2 inch), which is the standard H-series pitch. This measurement must match your pulley's tooth pitch exactly for proper meshing and synchronous operation. Mixing different pitch belts and pulleys — for example, using an H-belt on an L-series pulley — will result in poor performance, skipping, or belt damage.