Four Flute Downcut Finishing Roughing router bits have two flutes with finishing edges and two flutes with serrated edges and are used when feed speed is required to be high or there is a lot of material to remove from the workpiece. The compression geometry allows for great finish on top and bottom of the material. 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, router tables, handheld routers