Self-aligning ball bearings feature two rows of steel balls, a common sphered raceway in the outer ring, and two deep, continuous raceway grooves in the inner ring. These bearings are insensitive to angular misalignment of the shaft relative to the housing—such as that caused by shaft deflection or housing deformation—making them suitable for applications where such misalignment may occur. Under normal loads, the maximum permissible misalignment angle ranges from approximately 2° to 4°, depending on the dimension series. They are available in open and sealed versions, with a choice of cylindrical or tapered bores.