A ball end milling cutter is also known as a "ball nose mill". The end of this tool is ground with a full radius equal to half of the tool diameter, and the edges are center cutting.
They can be single end or double end and they can be made from solid carbide or various compositions of high speed steel. They can be general purpose or high perfomance geometries.
They can be used for milling a large corner radius, grooving with a full radius, and contour or profile milling. The smaller diameters can be used for engraving. They are available in a wide variety of standard sizes and lengths.