Niagara Cutter N55851 Carbide Ball Nose End Mill, Inch, Uncoated (Bright) Finish, Roughing and Finishing Cut, 30 Degree Helix, 4 Flutes, 2" Overall Length, 0.188" Cutting Diameter, 0.188" Shank Diameter Four flutes produce a better finish than fewer flutes and can machine material twice as fast as two-flute end mills in some applications 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 Uncoated (bright) tools have no additional surface treatment or coating for general-purpose applications Carbide can run at higher speeds than high-speed steel, resisting abrasion and high cutting temperatures