I received the follwing message:
Respected Sir,

Myself JAYDIPSINH SOLANKI studing in industrial engineering( 8th sem.).Recentely i'm doing work as a trainee on shot peening machine for metal sheet in harsha engineers ltd.(making precision bearing cage).
So, give me information on shot peening machine & difference between shot peening & shot blasting.Tell me also
- It's useful to use shot peening instead of shot blasting in making bearing cage ?
- benefits & draw backs of shot peening & shot blasting.

Shot blasting is used as a cleaning process to remove scale and grit etc. Shot peening is used to put compressive stress layer into surface of metal to help improve fatigue life. Shot peening is also used for forming and straightening. Either process might be applied to your bearing cage.
What is it that you want to accomplish? If it is deburring then use shot blasting. If it is fatigue strengh then use shot peening.