YRT bearings (rotary table bearings) are axial and radial combined cylindrical roller bearings, including two thrust

needle roller bearings and a radial cylindrical roller bearing with the combination of axial and radial preload,

For the convenience of transportation and fixing, two or three symmetrical screws are fastened to the two rings in

order to prevent rollers and rings generating collisions that influence bearing accuracy. https://www.efindbearing.com/rot...earing/yrt-bearings.html