Flexible Honing for Cross-Drilled Holes and Radiused Ports

The Flex-Hone® tool from Brush Research Manufacturing (BRM) removes burrs from cross-drilled holes, blends-in radiused ports, and improves surface finish inside of cylinders. Cutting, turning, and drilling metal parts creates burrs and unfinished edges that are often removed off-line in secondary operations. Using the Flex-Hone® tool, however, manufacturers can automate deburring and surface finishing operations, saving time and improving quality. 

As BRM’s new Flex-Hone® In-Machine Setup video explains, manufacturers who use flexible hones with CNC equipment can use a Jacobs-style chuck directly on the brush tool’s stem wire. BRM ball hones also mount in lathes, mills, drill presses, and electric hand drills. Self-centering and self-aligning to the bore, BRM cylinder hones are self-compensating for wear. The Flex-Hone® tool’s abrasive globules each have independent suspension and produce a plateau finish that optimizes oil retention.   

Deburring Tools for Cross-Drilled Holes

Drilling cross-holes creates burrs where the holes intersect. Manual deburring operations can be expensive and time-consuming, however, and some automated deburring tools require rigid and elaborate setups. To reduce production times and costs, BRM cylinder hones simplify the burr removal process. Because the Flex-Hone® is oversized for the bore, the tool “pops” out and into the intersection, removing cut, torn, and folded metal while creating a clean radius at the transition edge. 

As BRM’s new Flex-Hone® video demonstrates, flexible honing in a machine tool removes burrs efficiently and uniformly. Examples shown include cross-hole deburring in 7075 aluminum and the deburring of radial slots in 6061 aluminum. In addition to removing metal burrs that can cause part misalignments, BRM ball hones can achieve surface finishes in the single RA level.  By reversing the direction of the spindle, burr removal can be performed in both directions.

Surface Finishing and Port Radius

Flexible hones for radiused ports improve surface finish while removing burrs that can impede the flow of fluids, lubricants, and gases. Unlike rigid hones and honing stones, Flex-Hone® tools are not designed for heavy-duty or high-precision material removal. Made with abrasive globules permanently bonded to flexible nylon filaments, BRM brush tools follow existing geometry and will not affect size, ovality, or concentricity. As the website Tool Daddy explains, BRM ball hones are also “friendly” on port edges.

Cylinder honing for port deburring is used in a variety of industries, including the production of marine engines. As this application guide explains, a leading manufacturer once used emery cloth mounted on a fixed spindle machine to produce a port radius. To solve critical quality-control problems, however, the Mercury Marine began using machine-mounted Flex-Hone® tools instead.