Plummer blocks are bearing housings supplied without any bearings. They are usually meant for higher load ratings and corrosive industrial environments. The terms pillow-block and plummer-block are used interchangeably in certain parts of the world. The disruptive strength of plummer block varies depending on its type, nature and direction of a load working on it, as well as the flatness of a surface to which it is installed.
Split plummer block housings are generally used for self-aligning ball bearings, barrel roller bearings, and spherical roller bearings.