1Data based on stress to produce 5% relaxation in 7 days. Helical springs,
because of their configuration, are loaded in shear, and design stresses are based
on maximum shearing stress. The design of flat springs, however, normally involves
tensile stresses; therefore, values for flat springs do not consider shear strength.
2After coiling or fabrication.
3Use lower value for minimum rate of relaxation and higher value where
some initial relaxation and a higher rate of relaxation can be tolerated.