6321-SKF Open Deep Groove Ball Bearing 105x225x49mm. SKF Single row deep groove ball bearings are used in a wide variety of applications, they are simple in design, non-separable, suitable for high speeds and are robust in operation, and need little maintenance. Deep raceway grooves and the close conformity between the raceway grooves and the balls enable deep groove ball bearings to accommodate axial loads in both directions, in addition to radial loads.