Niagara Cutter N72863 Cobalt Steel Square Nose End Mill, Metric, Weldon Shank, Uncoated (Bright) Finish, Finishing Cut, 30 Degree Helix, 4 Flutes, 2.5" Overall Length, 5mm Cutting Diameter, 0.375" Shank Diameter Four flutes produce a better finish than fewer flutes Cobalt steel resists abrasion and high cutting temperatures, and has higher feed rates than high-speed steel Uncoated (bright) tools have no additional surface treatment or coating for use on a broad range of materials Square nose end mills (also called square end) create sharp, unrounded cuts Center-cutting design allows the end mill to plunge into material like a drill bit while also performing conventional surface milling