... the material of the cage can be steel plate or synthetic resin etc.Its specialty is that its outer race are ... allowed to be over 3 layers. Self-aligning ball bearingProducts nameSelf-aligning ball bearingCage materialChrome Steel or Carbon SteelPrecisionPO P6 P5 ... Bearing 61800,61900.16000,6000,6200,6300,6400,etc Thrust Ball Bearing 51100,51200,51300,51400,52200,52300etc Cylindrical RollerBearing ...