Outer spherical ceramic bearings can be divided into three categories based on their cooperation with the shaft:

1、 The code for the outer spherical ball bearing with top thread is UC200 series (light series), UC300 series (heavy series), and deformation product UB (SB) 200 series. If the application environment is not suitable, UC200 series is usually selected, otherwise UC300 series is selected. Usually, there are two top threads on the outer spherical ball bearing, with an angle of 120 °. Its characteristic is that when cooperating with the shaft, the top threads are used to push against the shaft and then have a fixed effect. However, the environmental requirements for cooperation require a small oscillation scale. This type of outer spherical ball bearing is widely used in various manufacturing professions such as textile machinery and ceramic machinery.

2、 The codes for tapered outer spherical ball bearings are UK200 series and UK300 series. This type of outer spherical ball bearing has a tapered inner hole with an inner diameter of 1:12, which needs to be used in conjunction with a tightening sleeve. The characteristic of this type of outer spherical ball bearing is that it can accept larger loads than those with top screws. Due to the fact that the inner diameter of the same type of tight fitting sleeve used in cooperation with it is smaller than that of the top threaded outer spherical ball bearing, for example, the inner diameter of the top threaded outer spherical ball bearing UC209 is 45mm, and the diameter of the shaft used in cooperation with it is 45mm. However, if it is replaced with a tapered outer spherical ball bearing, only the tight fitting sleeve with an inner diameter of 45mm can be selected, and the tapered outer spherical ball bearing used in cooperation with the 45mm tight fitting sleeve is only UK210 (of course, if it fits higher, UK310 can be selected). Therefore, the compatibility accepted by UK210 is much greater than that of UC209.

3、 The eccentric sleeve outer spherical ball bearings are designated as UEL200 series, UEL300 series, and SA200 series. The primary feature of this type of outer spherical ball bearing is that there is a certain degree of skewness at the upper end of the bearing, and a corresponding skewness sleeve with the same degree of skewness cooperates with it. This type of bearing can also be said to be a specialized bearing, as it is primarily used in agricultural machinery (harvesters, straw returning machines, threshers, etc.). This type of outer spherical ball bearing is mainly used in layouts with strong jumping, and cooperation in layout can effectively reduce strong jumping.