Pillow blocks can refer to a variety of bearing styles such as single row ball bearings, double row ball bearings, spherical roller bearings, taper roller bearings, etc. A unit is typically a reference for a 1-piece housing as opposed to a split housing. For simplicity, this article will focus on single row ball bearing units.

Pillow block bearing units are designed for quick, easy and safe mounting. They are sealed and pre-greased at the factory making them ready-to-use. Multiple sealing solutions and greases (including food grade greases) are available for specific application requirements. Some variants may be virtually maintenance-free depending on the application operating conditions. Because of the sphered outer ring interface, they can accommodate moderate initial misalignment, but normally do not permit axial displacement. These units offer a simple, cost-effective solution that can provide a number of benefits.