THK BK25 Ball Screw Support Bearing Unit BK25

The THK BK25 Ball Screw Support Bearing Unit is a fixed-side support for 25 mm ball screw shafts that uses factory-preloaded angular contact bearings to eliminate axial play while delivering high rigidity and precise axial positioning. Part of THK's BK Series, this square housing accepts a 25 mm shaft and pairs with THK BF25 floating-side units for accurate shaft alignment and long service life in demanding linear motion applications. Key specifications include: Shaft diameter 25 mm; shaft bore 25 mm; M25 × 1.5 thread compatibility; housing height 80 mm; width 106 mm; length 42 mm; housing material of high-strength steel/cast steel; bearing type factory-preloaded angular contact bearings with JIS Class 5 accuracy; fixed-end flange-mount installation; compatible floating support THK BF25; compatible ball screw series with BK25 shaft-end machining. Common applications encompass CNC machining centers, automated assembly systems, semiconductor equipment, packaging machinery, robotics, and other precision manufacturing equipment that rely on ball screw drives. It provides accurate shaft alignment, high load capacity, low runout, maintenance-free operation, and a compact, standardized design, making it suitable for new machine construction, retrofits, repairs, and replacement of fixed-end ball screw bearing assemblies by machine builders, maintenance technicians, and system integrators.