Each letter of the code name of the precision machine tool bearing represents an important parameter. Once the wrong choice is made, the consequences will be disastrous! Among them, angular contact ball bearings will indicate the contact angle of the steel ball. Common angles are C for 15°, AC for 25°, A for 30°, and B for 40°; in addition, there are 18°, 21° and other non-standard angles, the larger the contact angle, the greater the axial force the bearing can withstand, which is more suitable for low-speed and heavy-load applications; in the code of precision machine tool bearings, the selected cage material is generally indicated, TN stands for nylon cage, M stands for copper cage, J stands for iron cage, T stands for bakelite cage; different cages are suitable for different application scenarios, when selecting, be sure to confirm clearly, otherwise it will not be used; under normal circumstances , The structure of precision machine tool bearings can be judged by the bearing code. For example, bearings such as CTN and ACTN are external guide bearings, which are suitable for high-speed operation. The code contains CTN and ACTN, which means that such bearings are ball-guided bearings and are suitable for medium-speed operation. , if there is no such code, it is likely to be an inner guide structure, which is suitable for vulgar operation scenes; only when the torque is accurate can the rotation be stable!