Choose the bearing with the right contact angle. Bearings with two contact angles have different performance and application fields (as shown in Table 1). Select the bearing from the rolling element size and material. All spindle bearings in the model number B are large-size spheres, and the rest are small spheres. Large ball bearings have higher load carrying capacity than small ball bearings, so they are more suitable for high load applications. On the contrary, small ball bearings have better high-speed adaptability. Ceramic ball bearings have additional advantages in speed (see the spindle bearing parameter table). X-life ultra-long life bearings are composed of Cronidur30 ferrules and ceramic balls. Small spherical X-life bearings start with XC, and large spherical bearings start with XCB. The following comparison of specifications and performance parameters of spindle bearings is helpful for selecting suitable bearings. The contact angle is divided into: 15° 25°. Applicable performance options: radial stiffness, axial stiffness, radial system stiffness, radial bearing capacity, axial bearing capacity, radial and axial composite bearing capacity, higher speed and temperature difference between inner and outer rings, ΔT is large, and ΔT is small. Application area selection: Grinding machine, lathe, ultra-finishing machine tool, milling machine, drilling machine with transmission side bearing arrangement, machining center, electric spindle. Ball size/ball material load speed life bearing type large/steel ball high medium good B small/steel ball medium high good HS.. large/ceramic ball medium high good HCB.. small/ceramic ball low highest best HC... X-life super long life bearing is the best best best best XC.., XCB...