Tool material innovation is often the vanguard of machining work, with the recent industrial and scientific and technological development, cutting tool materials from carbon tool steel, high-speed steel, carbide steel and then to the composite materials, there has been a great progress. However, now the use of various types of cutting tools widely used in the use of short life and affect the production power of the problem, most of which is caused by the surface hardness and wear resistance is not high enough.

Later, people found in high-speed steel or carbide steel cutter surface coated with a layer of titanium nitride hard film, the function of the tool forward has a very unique role.
Titanium nitride is a proper and stable compound with excellent corrosion and oxidation resistance and attractive golden color, but its main use is not for decoration.
Titanium nitride coating has a hardness value in the Vickers hardness (HV) 2500 or more, in the tool coated with 3 ~ 5 micron titanium nitride coating, the tool will be able to have a higher wear resistance and heat resistance, a substantial advance in tool life and cutting power. For example, the gear hob by titanium nitride coating life can be extended by 3 ~ 4 times, and thus can be in the cutting gear can advance the cutting speed, thus reducing the processing time and cost.

Titanium nitride coating accumulation process for physical vapor accumulation (PVD), is in the vacuum conditions of titanium evaporation, and nitrogen reaction on the surface of the tool constitutes a layer of very hard composite film. The important feature of this process is that the temperature is only maintained at about 350°C during machining, so that the intrinsic properties and scale of the HSS tool are not affected.