Design information for engineers, such as spring calculation formulas,
which are the basis of spring design, can be found here.
A diagram of load characteristics is shown in Figure 6. If h0/t exceeds 1.4, the load will not increase even if the deflection increases when the spring height is close to its solid height.
This is a very interesting point from the viewpoint of spring users. A spring for a clutch uses these characteristics.
If these springs are stacked in series, however, some springs may invert and the load characteristics may not be satisfied.
It is, therefore, necessary to keep this value low for designs that require linearity.
Hysteresis occurs in the load characteristics of disc springs when decompressing, and the load is lower than when pressurizing.
This tendency increases as the number of springs stacked in parallel increases.
Care must be taken if the load used is decompression.