hardness distribution in the nitrided H13 substrates as shown in Fig. 5, it is possible to verify that the thin coating is harder than the thick coating. A reduction in hardness is expected at the thicker coating system, mainly due to the coarser columnar microstructure as shown in Fig. 6a and b, which shows the microstructure of the 3 and 8.3 μm coating thickness over nitrided case A, respectively.