Coatings are thin, hard films on cutting tools that boost hardness, reduce friction, and resist heat — letting tools run faster and last longer. Each type suits different work.
The main coatings
| Coating | Strength | Best for |
|---|---|---|
| TiN (gold) | General hardness, low cost | Steel, general purpose |
| TiCN | Harder than TiN | Abrasive materials, higher feeds |
| TiAlN / AlTiN | Excellent heat resistance | Steel, stainless, high-heat/dry |
| ZrN | Low built-up edge | Aluminum, non-ferrous |
| DLC | Very low friction | Aluminum, plastics |
How to choose
Match the coating to the material’s main challenge. High-heat metals (steel, stainless, titanium) favor TiAlN/AlTiN, which form a protective oxide at temperature. Gummy non-ferrous metals (aluminum) favor ZrN, DLC, or uncoated/polished tools, because standard steel coatings can promote built-up edge. Coatings help most when paired with correct speeds and feeds — they don’t rescue a bad cut.
Frequently asked questions
What coating for steel? TiAlN/AlTiN for its heat resistance.
What coating for aluminum? ZrN, DLC, or polished/uncoated.
Do coatings really help? Yes — more speed and tool life, when feeds/speeds are right.
A coating is only as good as the speeds and feeds behind it: run a heat-resistant coating too slowly and you’ll still get built-up edge, while running an aluminum-friendly tool too hot wastes its advantage. Match the coating, the material, and the parameters together.