Niagara Cutter N86164 Carbide Ball Nose End Mill, Inch, Uncoated (Bright) Finish, Roughing and Finishing Cut, 30 Degree Helix, 2 Flutes, 2.5" Overall Length, 0.250" Cutting Diameter, 0.250" Shank Diameter Two flutes offer better chip-carrying capacity than end mills with more flutes, enhancing the tools ability to remove material 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