Specifications: single-row deep-groove ball bearings are the most popular of the antifriction bearingtypes. They are available in a broad range of sizes, from miniature ball bearingswith outside diameter of less than 9mm to extra-large bearings that exceed1,500mm in diameter. Small and mid size bearings are also available in a varietyof shield, seal and snap ring arrangements. Big ones normally are fitted withsolid brass or steel cages.