Niagara Cutter N55772 Carbide End Mill, General Purpose, TiCN Coated, 4 Flutes, Square End, 1" Cutting Length, 3/8" Cutting Diameter Four flutes produce a better finish than fewer flutes Square nose end mills (also called square end) create sharp, unrounded cuts Titanium carbon nitride (TiCN) coating lubricates the end mill for high-temperature stability and offers better abrasion resistance than TiN coating 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