- Multilayer describes a variety of available coating options, such as nanometer-thick layers of alternating titanium nitride (TiN), aluminum oxide, and titanium aluminum nitride (TiAlN). Multiple layers of more than one coating material help prevent cracks in the finish from propagating through the tool, and provide benefits according to which elements are chosen for the different layers. The TiN/aluminum oxide/TiAlN multilayer coating, for example, is for finishing to roughing of steel and steel castings;this grade can handle continuous and interrupted cuts, and is a grade for a broad application area.
- TiAlN (titanium aluminum nitride) is a coating that is tough and has high oxidation stability, and helps extend the life of the tool. It becomes self-lubricating at higher speeds, making it ideal for cutting without coolant ("dry machining"). It is good for machining titanium, nickel-based alloys, cast iron, and stainless steel.
- TiCN (titanium carbonitride) is a coating that is harder and has lower friction than TiN. It combines toughness with good wear resistance. It is good for use on items made of ductile cast iron, stainless steel, aluminum, carbon steel, and plastic.
- TiN (titanium nitride) is a coating that combines hardness and low friction to help extend cutting tool life and permits faster cutting speeds than uncoated tools. It is good for use on items made of ductile cast iron, stainless steel, aluminum, carbon steel, and plastic.
- Uncoated (bright) tools have no finish or coating. They are a common choice for general-use applications.