Cast Iron Pillow Block Bearing is a pedestal that is used to provide support for a rotating shaft with the help of compatible bearings and various accessories. The assembly consists of a mounting block that consists of a house bearing. Cast Iron Pillow Block Bearing is a mounted anti-friction bearing that is contained within a solid cast iron. Ductile iron, housing unit. These are also referred to as a unit that is self-contained, sealed, greased, and ready for installation on the equipment.