What are the characteristics of coil springs

Due to the structural characteristics of the cylindrical spiral spring, within the elastic deformation range of the material, the relationship between the spring load “P” and the deformation amount “F” is not completely linear. As the deformation increases, the helix angle also increases. , The deviation of load and deformation from linearity is also large, but in general, the relationship between load and deformation is basically linear within the working deformation range of the spring, and the deviation from linearity is generally 1% to 3%.