Bearings are parts of the machine which are the most commonly used due to their importance. They reduce the friction between moving parts of the machine and the rolling motion of the bearings makes the movements smoother. In this study, we will discuss about heat treatments and fatigue performances of bearing balls. Most commonly material used for making ball bearings is 100Cr6 chrome steel. In this study we will discuss about bainite and standard martensite heat treatment processes of the bearing balls and steels. Bearings are composed of different metal components and they come in to contact with each other. Life of bearings is critical when they are used as industrial applications.