Roller Bearings are a type of rolling-element bearing that uses cylinders (rollers) to maintain the separation between the moving parts of the bearing (as opposed to using balls as the rolling element). The purpose of a roller bearing is to reduce rotational friction and support radial 4x12x4 Bearing and axial loads. Compared to ball bearings, roller bearings can support heavy radial loads and limited axial loads (parallel to the shaft). They can operate at moderate to high speeds .

Roller bearings — also known as rolling-element bearings — are similar to ball bearings in that they are designed to NSK 6004 Bearing carry a load while minimizing friction. However, roller bearings transmit loads using cylinder rolling elements, rather than balls, to maintain the separation between moving parts of the bearing.