Uncoated High-Speed Steel—Uncoated end mills are for general purpose milling and short production runs. They stay sharper than coated end mills when used on soft materials like aluminum, leaving a better finish.

Titanium Nitride (TiN)-Coated High-Speed Steel—Titanium nitride (TiN)-coated end mills create less friction than uncoated end mills, which means they last longer when run at similar speeds. Use coated end mills for demanding, high-speed jobs in hard material as well as for longer production runs. The coating reduces friction and vibration as they’re used, making them more wear resistant than uncoated end mills.

Titanium Carbon Nitride (TiCN)-Coated High-Speed Steel—Titanium carbon nitride (TiCN)-coated end mills have a hard, smooth finish that resists chipping and wear and prevents material from accumulating on the cutting edge. They’re especially good for use in aluminum. Use coated end mills for demanding, high-speed jobs in hard material as well as for longer production runs. The coating reduces friction and vibration as they’re used, making them more wear resistant than uncoated end mills.

Aluminum Titanium Nitride (ALTiN)-Coated High-Speed Steel— Aluminum titanium nitride (AlTiN)-coated end mills 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. Use coated end mills for demanding, high-speed jobs in hard material as well as for longer production runs. The coating reduces friction and vibration as they’re used, making them more wear resistant than uncoated end mills.