The nature of HSM generates less heat when compared to conventional machining, but the temperatures in the cut also are more constant. Therefore, more advanced physical vapor deposition (PVD) coatings are needed to sustain the cutting edge while it is engaged in the material.

Standard coatings such as titanium-nitride (TiN), titanium carbon-nitride (TiCN) and monolayered titanium aluminum-nitride (TiAlN) have been acceptable for most machining practices. However, HSM methods require much more out of the coatings and tools to sustain acceptable tool life.

Similar to that of carbide substrates, tool coatings often look similar to the naked eye, but differ drastically when placed under the microscope. In fact, the amount of variations on TiAlN alone is almost too vast to count as new versions are hitting the market monthly. Like carbide substrates, the process is what differentiates one coating from the next. In fact, the process is deemed so important that some manufactures have patented their processes in order to prevent them from being duplicated by their competition.

From a machining aspect, tests have shown that multilayered coatings are best for HSM applications . Multi-layered coatings, combined with other proprietary elements within each layer, prevent chips in the coating from penetrating all the way to the surface of the substrate. Instead, they deflect to the next layer, thus extending tool life significantly over that of regular mono-layered PVD coatings.