Niagara Cutter N89861 Carbide Square Nose End Mill, Double End, Inch, TiAlN Finish, Roughing and Finishing Cut, 30 Degree Helix, 4 Flutes, 2" Overall Length, 0.188" Cutting Diameter, 0.188" Shank Diameter Four flutes produce a better finish than fewer flutes Double-end square nose end mills create sharp, unrounded cuts and have cutting edges on both ends for longer tool life Stub length is used in applications with shallow depth of cut to increase the strength of the cutting edge and reduce the risk of breakage Titanium aluminum nitride (TiAlN) coating lubricates the end mill for high-temperature stability and abrasion resistance at high cutting speeds, offering better heat resistance than TiN and TiCN coatings Carbide can run at higher speeds than high-speed or cobalt steel, resisting wear and high cutting temperatures