71821 ACD/HCP4 angular contact ball bearing can bear radial load and axial load at the same time. It can work at high speed. The larger the contact angle, the higher the axial bearing capacity. The contact angle is the angle between the connecting line of the contact point between the ball and the raceway in the radial plane and the vertical line of the bearing axis. High precision and high-speed bearings usually have a contact angle of 15 degrees. Under the action of axial force, the contact angle will increase. Application: machine tool spindle, high-frequency motor, gas turbine, centrifugal separator, small car front wheel, differential pinion shaft, booster pump, drilling platform, food machinery, dividing head, repair welding machine, low-noise cooling tower, electromechanical equipment, coating equipment, machine tool slot plate, arc welding machine, etc.