Practically, the spring stiffness can be found by calculating the force divided by the displacement. You can find the stiffness of the string by determining the force. Force can be found by knowing the diameter of string, shear stress and mean coil diameter. As per spring stiffness formula, you will get to know about the stiffness of a spring based on the values of the number of coils, shear modulus, the diameter of spring, mean coil diameter and shear stress.

Where,

s = Spring Stiffness

n = Number of Coils

g = Shear modulus

d = Diameter of spring (metre)

m = Mean coil diameter (metre)

f = Spring Force

String stiffness is a measure of the resistance offered by the string to deformation. Every object in the universe holds some stiffness. The spring stiffness formula is very useful to determine the rigidity of a spring.