Union Butterfield 5270018 Cobalt Steel Square Nose End Mill, Inch, Weldon Shank, TiCN Finish, Roughing Cut, 4 Flutes, 3.25" Overall Length, 1/2" Cutting Diameter, 1/2" Shank Diameter Square nose end mills (also called square end) create sharp, unrounded cuts Roughing end mills (also called rougher) have chip-breaking cutting edges that remove material in less time than conventional end mills Number of flutes varies; fewer flutes have more chip-carrying capacity and more flutes produce a finer finish Titanium carbon nitride (TiCN) coating lubricates the end mill for high-temperature stability and offer better abrasion resistance than TiN coating Cobalt steel resists abrasion and high cutting temperatures, and has higher feed rates than high-speed steel