Shot peening machine is a process specifically designed to enhance the fatigue  strength of components which are subject to high alternating stress.It can help to  prevent  fatigue  cracks,corrosion,deteriorated  strength  and  premature fatigue that can be caused by machining and form metal parts which also creates internal stress concentration.It also helps to prevent crack formation and growth since typically fatigue cracks generally begin at the imperfection   on the surface of the material.