Belt Tensioning

What’s the best tension for my drive?

  • A general rule of thumb is that tension can be estimated by measuring the deflection of the belt at the middle of the span.  Under proper tension, the deflection should be about 1/64th the center distance.
  • A closer estimate can be obtained from the table below.
Belt section Small sheave dia. Tension in lbs.
Wrapped belt Cogged belt
Installation Re-tension Installation Re-tension
3V / 3VX ≤ 2.80” 45 35 55 45
> 2.80” ≤ 3.65” 55 45 70 55
> 3.65” ≤ 5.00” 80 55 90 70
> 5.00” M u s t   b e   c a l c u l a t e d
5V / 5VX ≤ 6.30” 150 110 160 120
> 6.30” ≤ 9.00” 160 120 190 150
> 9.00” ≤ 14.00” 200 160 220 180
> 14.00” M u s t   b e   c a l c u l a t e d
A / AX ≤ 3.15” 35 25 45 35
> 3.15” ≤ 4.12” 45 35 55 45
> 4.12” ≤ 5.20” 70 55 90 70
> 5.20” M u s t   b e   c a l c u l a t e d
B / BX ≤ 4.90” 70 55 100 80
> 4.90” ≤ 6.30” 90 70 110 90
> 6.30” ≤ 8.00” 110 90 135 100
> 8.00” M u s t   b e   c a l c u l a t e d
C / CX ≤ 8.00” 160 110 180 140
> 8.00” ≤ 9.75” 180 140 200 160
> 9.75” ≤ 14.00” 200 160 220 180
> 14.00” M u s t   b e   c a l c u l a t e d
  • The exact tension depends on specific drive information: the diameters of the sheaves, the center distance, the speed and horsepower, etc.  Contact our sales personnel for a drive calculation tailored to your specific drive.

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