For cnc milling, a carbide end mill or end mill that does not regrind should be used. In general milling, the second pass is used as much as possible. The first pass is best rough-milled with an end mill to continuously pass along the surface of the workpiece. The width of each pass is recommended to be 60%-75% of the tool diameter.
End mills and end mills with carbide inserts are mainly used for machining bosses, grooves and box surfaces.
Ball knives and round knives (also known as round nose knives) are often used to process curved surfaces and variable bevel profiles. The ball cutter is mostly used for semi-finishing and finishing. Round knives with carbide tools are mostly used for roughing.