The objective of this study was to investigate mechanical properties namely hardness of cemented tungsten carbide workpieces which were the mixture of 75 wt% tungsten carbide (WC) and 8 wt% -10 wt% cobalt (Co) as the binder . Other composites used included 0.5 wt% tantalum carbide (Tac) 14 wt% - 17 wt% titanium carbide (TiC) and 0.5 wt% - 1 wt% niobium carbide (NbC). The workpieces were then formed and sintered at 1450 °C. After the forming and sintering processes were completed the workpieces with different composites were obtained. The results showed that there were the differences in green density and hardness between recycled tungsten carbide powder and commercial tungsten carbide powder workpieces. Different particle characteristics and chemical components of tungsten carbide powder resulted in poor flow between the particles affecting density and hardness. Besides the compression of the metal powder before sintering could reduce the porosity because low porosity led to less shrinkage during sintering as shrinkage during sintering varies with the workpiece density after forming