In the last few years the firearms industry and the knife industry to a certain extent have embraced machine tool coatings with an increasing frequency. Machine tools like endmills, lathe inserts etc are bits of metal that are spun at high speed into other bits of metal to make things. For instance depending on the diameter of steel the lathe insert can be cutting with the steel contacting it at over 2000RPM. This creates a ton of heat from the friction (believe me I have the chip burns to prove it) and in a normal untreated insert or endmill this would wear the tool down. Thankfully coatings such as DLC(diamond like carbon) and TiN(titanium nitride) have come onto the scene.