Niagara Cutter N55681 Carbide Square Nose End Mill, Inch, Uncoated (Bright) Finish, Roughing and Finishing Cut, 30 Degree Helix, 4 Flutes, 3" Overall Length, 0.250" Cutting Diameter, 0.250" Shank Diameter Four flutes produce a better finish than fewer flutes Square nose end mills (also called square end) create sharp, unrounded cuts Carbide can run at higher speeds than high-speed steel, resisting abrasion 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