Diffusion bonding is a process whereby two materials are pressed together at high temperature and pressure for a period of time sufficient for atomic diffusion leading to bonding. To facilitate this process, a filler material, such as nickel alloy, is used at the interface between the two materials. In this study, precision machining tools were fabricated using a polycrystalline diamond tip and WC-Co shanks via diffusion bonding with paste type and sheet type nickel alloy filler metals. Experiments were conducted to determine the bonding characteristics of the fabricated cemented carbide test specimens with respect to the metal filler type used, as well as the copula shape. The bonding joint was examined for uniformity and crack and void formation using an optical microscope and micro X-ray computed tomography. Our results indicated the presence of cracks near the junction for all conditions. The tensile strength of the bond was measured for WC-Co proportional test specimens using a universal testing machine with respect to the metal filler type and copula shape. The tensile stress results were similar among the samples tested; however, our results indicated that the pressure distribution of the bond played an important role in the resulting bond strength.