Needle roller and cage assemblies are self­-contained, ready-­to­-mount bearings. In applications where the shaft and housing bore can serve as raceways, the assemblies can be used to create bearing arrangements that require minimal radial space.

Needle roller bearings are smaller than general bearings but have a greater loadcarrying capacity. This advantage allows for more compact designs for bearings as well as for bearing housings. Use of these bearings lowers costs by allowing for lighter-weight machinery and more compact structures. compares bearings with (30) mm bore diameters. Needle roller bearings have 2 to 8 times the load-carrying capacity per given mass than other bearing types.

Needle roller and cage assembly bearings differ from general bearings in that, if the shaft and bearing housing can be made to a specific hardness, accuracy, and surface roughness, the needle roller and cage assemblies can function as independent bearings without inner and outer rings. Bearings used in this way are smaller and can be used in the same space as a metal bearing.