Spring design, in many instances, is still a trial-and-error process. The underlying reason is the large number of complex variables which must be related to the allotted space which the spring will occupy and to the desired loads throughout the working range. This paper presents a system of parameters which enables the spring designer to graphically portray these variables for a given problem. Derivations are based on the total number of coils as well as the outside diameter which accurately defines the entire space required for the spring. Charts are presented for springs with two dead coils and a torsion modulus of 11,500,000 psi.
Discussion: “Dimensionless Parameters for Helical Compression Springs” (Erisman, R. J., 1960, ASME J. Eng. Ind., 82, pp. 439–442)