Top threaded outer spherical ball bearings: Their code names are UC200 series (light series), UC300 series (heavy series), and deformation product UB (SB) 200 series. If the application environment has a small fit, the UC200 series is usually selected, otherwise the UC300 series is selected. Usually, there are two top wires on the outer spherical ball bearing, with an angle of 120 °. Its characteristic is that when cooperating with the shaft, the top wire is used to push against the shaft and then fix it, but the environmental requirement is that the oscillation amplitude should be small. This type of outer spherical ball bearing is widely used in various industries such as textile machinery and ceramic machinery.

The main advantages of outer spherical ceramic bearings are:

1. Due to the fact that ceramics are almost not afraid of corrosion, ceramic rolling bearings are suitable for operation under harsh conditions filled with corrosive media.

2. Due to the lower density and lighter weight of ceramic rolling balls compared to steel, the centrifugal effect on the outer ring during rotation can be reduced by 40%, thereby greatly extending their service life.

3. Ceramics are less affected by thermal expansion and contraction than steel, so when the clearance between bearings is constant, bearings can be allowed to work in environments with significant temperature differences.

4. Due to the higher elastic modulus of ceramics compared to steel, they are less likely to deform under stress, which is beneficial for improving working speed and achieving higher accuracy.