2 Bolts Flanged Cast Housing Mounted Bearings UCFL-203: Pillow block bearing are a form of mounted bearing used to provide load support for a rotating shaft. Selection of the appropriate bearings can be accomplished based on the shaf t size and the radial and thrust load requirements. Pillow block bearings are designed to support a shaft: the mounting surface is on a parallel line with the axis of the shaft. Elongated bolt holes in the base or feet of the unit allow for some adjustment and easy mounting of the pillow block bearing.