Flex Hone 4" HD Engine: GBD-series abrasive bead style brushes for block cylinders or liners have globe-shaped abrasive points on an independent suspension for self-centering, self-aligning to the bore, and self-compensating for wear. This reduces set-up time and costs and the need for special operator training, as well as ensuring precise control of finish parameters. The resilient, flexible honing tool has a soft cutting action to create a plateau finish, where surface irregularities are reduced, while retaining a cross-hatch suitable for oil retention; the plateau finish increases the bearing area of the surface. Order by actual bore size as the tool is produced oversized.