Most of tool steel dies were usually surface treated by the duplex coating, where the tailored coating was deposited onto the prehardened die surface. High density plasma nitriding was employed to preharden the SKD11 dies. Then, the nano-laminated DLC coating was deposited with the chromium based interlayers. In the former, both RF- and DC-plasmas were independently generated to accommodate high-density plasma state. Without mechanical matching between input and out powers, automatic frequency control around 2 MHz leaded to stable plasma nitriding. In the latter, the RF-sputter was utilized to coat the DLC nano-laminate, which was composed of two sub-layers with different mass density. Direct control of bias voltage and pressure enables us to vary the mass density and hydrogen content. First, the mechanical properties and micro-structure were analyzed both for the prehardened SKD11 and the nano-laminated DLC-coating. The tribological performance was compared to the DLC nano-laminated SKD11 specimens with and without prehardening. Significant difference in the tribological performance revealed that the prehardening by plasma nitriding was indispensable in the duplex method. The transfer stamping system was employed as a metal-forming simulator to investigate the formability of brass sheet in semi-dry stamping by using the series of the duplexed dies. No defects or loss of surface quality were seen on the brass book even after continuous transfer-stamping for 100,000 shots under the minimum quantity lubrication condition.