Niagara Cutter N98163 Carbide End Mill, General Purpose, TiN Coated, 4 Flutes, Square End, 1-1/2" Cutting Length, 1" Cutting Diameter Four flutes produce a better finish than fewer flutes Square nose end mills (also called square end) create sharp, unrounded cuts Titanium nitride (TiN) is a general-purpose coating that combines high-temperature resistance and increased hardness compared to uncoated end mills Carbide can run at higher speeds than high-speed steel, resisting abrasion and high cutting temperatures Center-cutting design allows the end mill to plunge into material like a drill bit while also performing conventional surface milling