Milling produces a flat or contoured surface on a workpiece with a rotating tool. The work can be done on a machining center or milling machine, and can also be done on a turning center that has rotary or “live tool” capabilities. The tools for milling include both solid tools and “indexable” tools—the latter consisting of a tool body that uses replaceable cutting inserts. Carbide is the most likely material for milling tools, though other options include high speed steel as well as, ceramic, cermet and diamond tools for certain more demanding applications. The end mill can be flat-bottomed for flat surfaces, or ball-nosed for milling up contoured shapes. Another common milling tool variety is the “face mill,” a generally larger-diameter tool designed for efficiently milling a wide, flat surface in an economical number of passes.