Niagara Cutter N70153 Cobalt Steel Square Nose End Mill, Inch, Weldon Shank, Uncoated (Bright) Finish, Roughing Cut, 30 Degree Helix, 4 Flutes, 3.75" Overall Length, 0.750" Cutting Diameter, 0.750" Shank Diameter Roughing end mills have chip-breaking cutting edges that remove material in less time than conventional end mills Coarse-pitch tooth design is suitable for machining soft, gummy materials Number of flutes varies by diameter for optimum feed and cut rate Cobalt steel resists abrasion and high cutting temperatures, and has higher feed rates than high-speed steel Square end creates sharp, unrounded cuts and has a corner chamfer to strengthen the cutting edges