A plummer block is differ from pillow block which are bearing housings supplied without any bearings and are usually meant for higher load ratings and a separately installed bearing.

The fundamental application which is to mount a bearing safely enabling its outer ring to be stationary while allowing rotation of the inner ring. The housing is bolted to a foundation through the holes in the base. Bearing housings is split type. Split type housings are usually two-piece housings where the cap and base may be detached. Various sealing arrangements may be provided to prevent dust and other contaminants from entering the housing. Thus the housing provides a clean environment for the environmentally sensitive bearing to rotate free from contaminants while also retaining lubrication, either oil or grease, hence increasing its performance and duty cycle.