Chain Sag (S) Calculator







Formula

The formula to calculate the Chain Sag (S) is:

S = \(\frac{w \cdot l^2}{8 \cdot T}\)

Where:

What is Chain Sag?

Chain sag refers to the vertical displacement or droop of a chain or cable under its own weight and tension. It is an important factor in engineering and construction, as excessive sag can affect the performance and safety of the structure. To calculate the chain sag, square the length of the span, multiply by the weight per unit length, then divide by the product of 8 times the total tension.

Example Calculation

Example 1:

Calculation:

S = \(\frac{0.5 \cdot 100^2}{8 \cdot 200} = \frac{0.5 \cdot 10000}{1600} = \frac{5000}{1600} = 3.125\) inches

Example 2:

Calculation:

S = \(\frac{0.3 \cdot 150^2}{8 \cdot 300} = \frac{0.3 \cdot 22500}{2400} = \frac{6750}{2400} = 2.8125\) inches