Self-aligning ball bearings Self-aligning ball bearings are double row bearings with spherical outer ring groove with aligning ability to compensate middle error, shaft deformation and housing deformation.The bearings can not be dismantled with cylindrical or tapered bore. from WD Bearings, WD Bearings, Quality Creates Value WD Bearings,Quality Creates Value! BSI ISO9001 ISO14001 certified. www.wd-bearing.com