Miniature bearings mainly bear radial loads and have the advantages of high speed and low noise. It is widely used in precision instruments, micro motors, household appliances, medical equipment, electric tools, computer appliances, fitness equipment, fishing gear, remote control toys and other related fields. And bearings vary in size from small to large. So from micro bearings with dimensions of only a few millimeters used for micro motors/medical equipment to ultra large bearings with outer diameters of several meters and weights of over ten tons used in shield tunneling machines.