L-Type Timing Belt 12.7mm Wide Closed Loop Synchronous Belt — 86L to 938L

The "L" number is the tooth count. Multiply by the L-pitch (9.525mm / 0.375" per tooth) to get the belt's inner circumference. For example, 86L = 86 × 9.525mm = 819.15mm (≈32.25"). Match this circumference to your drive system's required belt path length, which depends on pulley center distance and sprocket tooth counts. When replacing an existing belt, the easiest method is to count the teeth on the old belt or read its part number directly.

The "C" value is the belt's inner circumference in millimeters, calculated as tooth count × 9.525mm. For example, 86L has C = 219.075mm (≈8.62"). This is the key dimension to match against your drive system's required belt path length. Always verify the C value — not just the L number — before ordering, especially if you are sourcing a replacement for a non-standard or imported machine.

L-type synchronous belts are generally rated for moderate-to-high torque transmission in industrial and light-duty automation applications. Exact load ratings depend on belt material, pulley diameter, operating speed, and wrap angle. Typically, fiberglass-reinforced neoprene L-belts handle tensile loads in the range of several hundred to over a thousand Newtons. Contact us to confirm specifications for your specific application.

L-type timing belts are typically constructed from neoprene rubber with fiberglass tension cords, which generally offers good resistance to oil, moderate heat, and humidity. However, prolonged exposure to UV radiation, standing water, or harsh chemicals may reduce belt life. For outdoor installations or washdown environments, confirm material compatibility with your specific conditions before installation.

These belts follow the standard L-pitch (3/8" pitch = 9.525mm tooth spacing) and are 12.7mm (1/2") wide. They are compatible with any standard L-series timing pulley conforming to the trapezoidal tooth profile — specifically L-pitch pulleys. Verify your pulley's pitch designation and belt width before ordering. Do not use with XL-pitch (5.08mm), H-pitch (12.7mm), or other non-L-pitch pulleys.

Select Qty = 1 for a single direct replacement belt. Select Qty = 2 if your machine uses a matched pair — common in dual-drive systems, parallel-axis conveyors, or gantry-style CNC machines — or if you want a spare on hand to minimize future downtime. The 2-piece option is priced at a slight per-unit discount compared to purchasing two singles separately.

Loosen the motor mount or tensioner to reduce the center distance between pulleys. Slip the belt over both pulleys without forcing it over the flanges. Re-tension the drive according to your system's specification — typically the belt should deflect approximately 1/64" per inch of free span under light finger pressure. Over-tensioning accelerates bearing wear; under-tensioning causes tooth skipping. Always re-check tension after the first few hours of operation.