In a sleeve or plain bearing, the axle and the bearing move in opposite directions on a sliding surface. By contrast, the two components of a rolling bearing that move towards one another – the inner and outer rings – are separated by rolling elements. This design generates significantly less friction than a sleeve bearing.
Bearings can transmit loads in a radial direction or an axial direction (thrust) and in many cases there is a combination of both radial and axial loads to transmit.
The inner and outer ring are typically made from a high-purity, chrome alloy steel. This material has the necessary hardness and purity important factors for high load ratings and a long service life.
(Wikipedia )
These products are made with high-quality steel and can be fitted specifically to your application.