UCP204-12 FYH Bearing Pillow Block Bearing Cylindrical bore (with set screws) 3/4" inch Inner Diameter Bearing This is the most common type of mounted ball unit. The rib at the bottom of the housing mounting section provides for a robust unit that can withstand great loads from any direction. it is used for applications with severe loading and shock load conditions. Tapered-bore style units are offered individually and adapters are sold separately.