The assembly symbols of various precision angular contact ball bearing assembly methods are shown in Figure 4.1. The assembly sequence and load bearing direction of assembled bearings are very important. Therefore, as shown in Figure 4.1, the outer ring outer diameter surface of the assembled bearing has '<' indicating the assembly mark, so that the order of assembly can be confirmed. If the bearings can be assembled in the correct order, a '＜' mark will be formed on the outer diameter of each bearing. DB DF DT FFB u200bu200bBFF FFF FFBB BBFF FFFB BFFF. The front side plane difference (Af) and the back side plane difference (Ab) of freely assembled angular contact ball bearings are adjusted to the same in advance, no matter which combination method, the specified preload can be obtained (Figure 4.2) Freely assembled angular contact ball bearings It is provided in accordance with a single product (combination symbol: U) or 2 combinations (combination symbol: DU). When two sets are provided, the mutual deviation of inner diameter and outer diameter is controlled. When using a single product, please select a bearing that is close to the actual measured value of the inner and outer diameter. The free assembly type of the TAB series of ball screw support bearings is marked with the assembly symbol '＜' on the outer diameter of the outer ring. Please refer to Figure 4.3 for the relationship between the combination method and the combination symbol. Free assembly bearing assembly method and assembly mark direction (only for ball screw support bearing TAB series).