T15 is used for cutting tools that are exposed to extremely rigorous heat or abrasion in service. The M tool steels generally are considered to have molybdenum as the principal alloying element, although several contain an equal or a slightly greater amount of such elements as tungsten or cobalt.
Titanium nitride (TiN) coating is wear resistant, inert & reduces friction. Used on cutting tools punches etc improving tool life 2-10x over uncoated tools
