Shot Peening Techniques for Greater Fatigue Life In Springs

Author:  Robert A. Bell
Source:  SPRINGS, Oct 1984 p.61-66
Doc ID:  1984136
Year of Publication:  1984
Abstract:  
A long-accepted practice for extending the fatigue life of high duty springs is shot peening. According to historians, this process was discovered by accident at a time when improving the performance of automotive valve springs was of paramount importance to the rapidly expanding automotive industry. The story goes that some engineers felt that clean springs might give better fatigue life and, to that end, parts were tumbled in sand to remove all of the extraneous matter from the surface of the wire. While this procedure produced some small improvement, it left much to be desired in the final evaluation but, since clean components did perform better than dirty parts, the operation was added to the manufacturing specifications for valve and other types of high-performance springs.