What is face milling cutters?:
Face mill. A face mill is a cutter designed for facing as opposed to e.g., creating a pocket (end mills). The cutting edges of face mills are always located along its sides. As such it must always cut in a horizontal direction at a given depth coming from outside the stock.
Face milling cutters are specialized cutting tools used for milling flat surfaces on a workpiece. They are commonly used in manufacturing and metalworking industries to produce a wide range of flat surfaces on different materials, including metals, plastics, and composites.