MACHINING Copyright Goodheart-Willcox Co., Inc. Chapter 26 Milling Machines 449 • The shell end mill, Figure 26-17, is a larger cutter 7 7 designed for both conventional face milling and end milling. It has teeth similar to the multi- flute end mill, but is mounted differently than a straight-shank end mill. • A ball end mill, also known as a ball-nose end mill, has a radius on the end or nose of the cutter, Figure 26-18. This cutting tool is frequently used to produce dies and molds because it can mill three-dimensional (3D) surface contours, fillets, and pockets. Face Milling Cutters Face milling cutters, or face mills, are used to machine large flat surfaces parallel to the face of the cutter, Figure 26-19. The teeth are designed to make the roughing and finishing cuts in one operation. Because of their size and cost, most face milling cutters have inserted cutting edges. Goodheart-Willcox Publisher Figure 26-17. Three shell end mills with indexable inserts. Mitsubishi Materials USA Corporation Figure 26-18. Ball end mills have a rounded tip. Goodheart-Willcox Publisher Mitsubishi Materials USA Corporation Figure 26-19. Insert selection is based on the material being machined. A—The replaceable inserts on this face mill are mechanically clamped in place on the cutter body. As the cutting edges wear, the inserts can be turned (indexed) to present a fresh cutting edge. B—An example of a face mill with indexable inserts. A B B B B B B Indexable insert Clamping device Cutter body