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Belt type L timing belts

9.525mm (0.375″) pitch · Trapezoidal teeth · Imperial sizes

L timing belts have a 9.525mm (0.375″) pitch and the classic trapezoidal tooth. You’ll find them on machine tools, packaging machinery, pumps, textile machines and medium-duty industrial drives, and on plenty of older and American-built machinery. They give a positive, slip-free drive with no stretch, so timing and speed stay exact. Search by the code on the old belt, such as 255L100, and use the filters to narrow it down by length or width.

  • Pitch9.525mm (0.375″)
  • ToothTrapezoidal, imperial
  • Example255L100
  • Teeth68 on a 25.5″ belt
  • Widths050 to 100 width codes

Finding the right L belt

Reading the code255L100 is a 25.5″ pitch length belt (the first number is the length in tenths of an inch), L pitch, 1″ wide. The last three digits are the width in hundredths of an inch. Common widths are 050 (1/2″), 075 (3/4″) and 100 (1″).

Counting teethPitch length divided by the pitch gives the tooth count. A 25.5″ L belt has 68 teeth. If the code has worn off, counting the teeth is the most reliable way to get the length.

L or T10?An L belt is 9.525mm pitch; T10 and AT10 belts are 10mm. They’re close enough to confuse but not to swap, so measure carefully and match the pulley.

Tip: For the drive, we stock matching L timing pulleys and imperial taper lock bushes. For serpentine drives, see DL double-sided belts. Note: belts cut to width or length to order can’t be returned unless faulty, so check the pitch, length and width before ordering.
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