Deep groove ball bearings are the most widely used bearings. Deep groove ball bearings are versatile, self-retaining bearings with solid outer rings, inner rings and ball and cage assemblies. They utilize an uninterrupted raceway that makes them optimal for radial loads .This design permits precision tolerance, and Due to their low frictional torque, they are suitable for high speeds. They are available in single and double row designs. In addition to open type bearings, these bearings often have steel shields or rubber seals installed on one or both sides and are prelubricated with grease. Also, snap rings are sometimes used on the periphery. As to cages, pressed steel ones are the most common.