Self-aligning ball bearings are constructed with the inner ring and ball assembly contained within an outer ring that has a spherical raceway. This construction allows the bearing to tolerate a small angular misalignment resulting from deflection or improper mounting. It is particularly suitable for applications where considerable shaft deflections or misalignment are to be expected. Additionally, the self-aligning ball bearing has the lowest friction of all rolling bearings, which enables it to run cooler even at high speeds. 1) Bearing series: 1200 series, 1300 series, 2200 series, 2300 series 2) Material of rings and balls: chrome steel, GCr15 and GCr15SiMn 3) Material of cage: steel cage, nylon cage or brass cage 4) Precision: P0 - P6 5) Vibration: Z1 - Z3 6）Clearance: C0 - C5 7) Application: Precision instruments, low noise motor, automobile, motorcycle, metallurgy, rolling mill, mine, petroleum, paper, cement, sugar and other industries and general machinery.