Upcut bits are the go to choice where having a clean bottom surface or getting maximum chip evacuation is most important. The up cut action of the bit pulls the chips up and out of the cut allowing for maximum chip evacuation. Because the chips are being pulled up this will result in a clean bottom edge of the cut

The basic edge-forming bit, the corner-rounding bit rounds an edge to a given radius. The tool is shouldered to cut a fillet. The cut can be used to ease edges, as a simple profile, or as a part of a complex one.