Preconforming a leaf spring
Springs - Bending stresses

To preform a leaf spring, each metal element must be deformed under the conditions represented by point H in figure 10 .

When the spring is a solid of equal strength, as is practically the case with an equal-leaf spring, it is sufficient to apply a suitable overload to the spring to bring all the spring material into the required condition. The operation gives the spring a permanent deformation that manifests itself in a loss of geometric deflection Δϕ that must have been foreseen...