Ball bearings are normally used in a mechanical setup to reduce friction between objects. Ball bearings operate on the principle of the roller-based bearing which means placing spherical elements between two pieces to reduce load and friction. Bearings are designed to reduce friction by using smooth metal balls or rollers along with a smooth inner and outer metal surface for the balls to roll against. These balls or rollers bear the load, which enables the device to spin smoothly without any friction.
The load in ball bearings is transmitted from the outer race to the ball and from the ball to the inner race. Because the ball is a sphere it only contacts the inner and outer race at a very small point and this helps it to spin very smoothly. However it also means there isn’t much of a contact area holding that load, so if the bearing happens to be overloaded the balls can deform or squish and the bearing can be ruined.
Ball bearings are the most common type of bearing and they are used in everything from inline skates to computer hard drives and the most common usage of ball bearings throughout the world is in the bicycle. These bearings are made to handle both radial and thrust loads, and are generally found in applications where the load is relatively small. Ball bearings are used in many walks of life and industry is just one of them as they are used in a wide array of industrial applications. A typical industrial-grade ball bearing must be friction resistant and have sufficient load bearing capacity. Ball bearings are normally made of steel or nickel and most ball bearings are available in a single row design.
Ball bearings are relatively easier to make than other rolling substances and can support a high degree of axial and radial pressures. However, the ball bearing's load bearing capabilities are comparatively lesser than other bearings.
Ball bearings are available in some common designs such as: radial balls, angular contact balls, axial balls and slot-filled ball bearings. The Anti-Friction Bearing Manufacturers Association (AFBMA) has a set of grades for bearing balls.