The Effect of Presetting Helical Compression Springs

A procedure for predicting the increase in fatigue load carrying capacity due to presetting helical springs is developed, based on the actual stress-strain curve of a material. Reasonable correlation with experimental results is obtained. For the cyclic load conditions and the material chosen, an increase in load carrying capacity of 21 per cent was observed. It is expected that an increase of approximately 40 per cent could be realized with slight modification of fabrication techniques.