Ring and ball contact angle between the standard contact angle of 15 °, 30 ° and 40 ° contact angle greater axial load capacity of the smaller contact angle is more conducive to high speed single row bearings can bear radial DB load and axial load combinations, DF combination and double row bearings can bear radial load and bi-axial load DT combinations for a larger axial load, a single bearing rated load with speed less than the occasion bearing ACH small diameter ball, the ball a few more, mostly for machine spindle angular contact ball bearings for high-speed and high precision rotating structure for the back of the combination of the two single row angular contact ball bearing inner and outer rings sharing can bear radial load and bi-directional axial load without filling slot type bearings are mainly used in a sealed cage: steel stamping cage (... a separate bowl; S-shaped, crown-shaped double row ...) copper alloy or phenolic resin retainer cut system, synthetic resin forming frame main purposes: single: machine tool spindles, high frequency motors, gas turbines, centrifuges, small car front wheel, the differential pinion shaft double row: pump, blower, air compressor, various types of transmission, fuel injection pumps, printing machinery