Niagara Cutter N98653 Carbide End Mill, General Purpose, TiN Coated, 4 Flutes, Ball End, 3/16" Cutting Length, 1/16" Cutting Diameter Four flutes produce a better finish than fewer flutes Titanium nitride (TiN) is a general-purpose coating that combines high-temperature resistance and increased hardness compared to uncoated end mills Carbide can run at higher speeds than high-speed steel, resisting abrasion and high cutting temperatures Ball nose end mills (also called ball end) create contoured surfaces Center-cutting design allows the end mill to plunge into material like a drill bit while also performing conventional surface milling