Deep groove ball bearings are the most common type among rolling bearings.​

A basic deep groove ball bearing consists of one outer ring, one inner ring, a set of steel balls, and a set of cages. Deep groove ball bearings are available in two types: single-row and double-row. In terms of structure, they can also be divided into sealed and open designs. The "open design" means the bearing has no sealing structure, while sealed deep groove ball bearings are categorized into dust-sealed and oil-sealed types. The dust seal cover is made of stamped steel plates, which only serves to simply prevent dust from entering the bearing raceways. The oil-sealed type adopts a contact-type oil seal, which can effectively prevent the lubricating grease inside the bearing from leaking out.​

The type code for single-row deep groove ball bearings is "6", and the code for double-row deep groove ball bearings is "4". With a simple structure and easy application, they are the most widely produced and extensively used type of bearings.​