The value of the spring constant depends on the elastic properties of the spring.
We know that, in an ideal spring, the spring force is proportional to the displacement (x) of its ends from the equilibrium position. So, according to Hooke’s Law,
Fs = -kx
Where Fs is the spring force, x is the displacement from the equilibrium position and k is the spring constant.
The spring constant is the characteristic property of the spring. It depends upon the material of construction and is measured in the units of N m-1.