Flutes have a low helix angle to provide the cutting forces required for difficult-to-machine material, such as hardened steel and iron. Made of solid carbide, these end mills are harder, stronger, and more wear resistant than high-speed steel and cobalt steel for the longest life and best finish on hard material. Their extreme hardness means they are brittle, so a highly rigid setup, such as a CNC machine, is necessary to prevent the end mill from breaking. They have a ball end for milling rounded slots, slopes, and contours. All are center cutting, allowing plunge cuts into a surface.

A titanium-aluminum-nitride (TiAlN) or aluminum-chromium-nitride (AlCrN) coating allows them to dissipate heat better than other end mills, especially at high speeds. At high temperatures, the coating creates a layer of aluminum oxide that transfers heat to the chips, keeping the tool cool, even when used without lubrication. This makes these good for aggressive machining while roughing or making interrupted cuts.