CNBTR HSS Adjustable Hand Reamer Metal Hole Cutting Tool Replacing Part (6.0-6.5 mm) Reamer Material: HSS Hinge tool with one or more teeth to cut holes machined surface of the thin metal layer rotary tool. After the hole reamer processing can be obtained the exact size and shape. Reamer is mainly use for improving the precision holes, reducing the surface roughness. Applies to: Reamer for reaming the workpiece has been drilling (or reaming) hole processed.