The open photoacoustic cell technique (OPC) was carried out in order to measure the thermal diffusivity of hardmetal. Hardmetal is usually processed by the conventional powder technology techniques: mix of WC + Co powders, compacting, and liquid phase sintering A new method to process hardmetal parts is hereby described. Parts of WC-15%wt Co were processed by using high pressure – high temperature sintering. It was used the pressure of 5GPa, temperature of 1350 oC, and time of 2 minutes of sintering. In addition to the thermal diffusivity, heat capacity was considered and the thermal conductivity achieved. Results matched with the values of the literatures where others photoacoustic techniques have been employed. It was achieved a thermal capacity of 3.34J/cm3K, thermal diffusivity of 0.35cm2/s, and thermal conductivity of 116.9W/mK. It reveals that the HPHT processed WC- 15%wtCo hardmetal is able to work as a cutting tool, in the thermal point of view.