Four Flute Upcut Finishing Roughing router bits have two flutes with finishing edges and two flutes with serrated edges and are use used when feed speed is required to be high or there is a lot of material to remove from the workpiece. The upshear geometry facilitates faster and more effective chip removal. The common applications are sizing, trimming and removing lots of material quickly. Increase the number of flutes if faster feedrate is required. Great for solid wood, veneered plywood and a variety of other materials. Used on 5 axis, point-to-point machines.