After the ina bearing is installed, in order to check whether the installation is correct, the operation inspection shall be carried out. Small machinery can be rotated by hand to confirm whether it rotates smoothly. The inspection items include poor operation caused by foreign matters,scars and indentation, unstable torque caused by poor installation and poor processing of mounting Ina Angular Contact Ball Bearing base, excessive torque caused by too small clearance, installation error and sealing friction, etc. If there is no abnormality, the power operation can be started.