Precision Twist E3304 Carbide Square Nose End Mill, Uncoated (Bright) Finish, 30 Deg Helix, 4 Flutes, 4" Overall Length, 1" Cutting Diameter, 1" Shank Diameter Suitable for machining steel, hardened steel, steel alloys, stainless steel, cast iron, copper, brass, bronze, aluminum, and aluminum alloys Four flutes produce a better finish than fewer flutes Carbide can run at higher speeds than high-speed or cobalt steel, resisting wear and high cutting temperatures Uncoated (bright) tools have no additional surface treatment or coating for use on a broad range of materials Center-cutting design allows the end mill to plunge into material like a drill bit while also performing conventional surface milling