The bearing blocks are available as metric sizes and inch sizes. A bearing block, also known as a plummer block or bearing housing, is a pedestal used to provide support for a rotating shaft with the help of compatible bearings & various accessories. Housing material for a pillow block is typically made of cast iron or cast steel.
Bearing blocks are usually mounted in cleaner environments & generally are meant for lesser loads of general industry. These differ from "plummer blocks" which are bearing housings supplied without any bearings & are usually meant for higher load ratings & corrosive industrial environments. However the terms pillow-block & plummer-block are used interchangeably in certain parts of the world.