In this study the effects of the cutting-tool coating material and cutting speed on the cutting forces and surface roughness were determined using the Taguchi experimental design. For this purpose, the nickel-based superalloy Hastelloy X was machined under dry cutting conditions with three different cemented-carbide tools. The main cutting force, F-z, is considered to be the cutting force as a criterion. The mechanical loading and the abrasiveness of the carbide particles have an increasing effect on the cutting forces. According to the results of the analysis of variance (ANOVA), the effect of the cutting speeds was not important. Depending on the tool-coating material, the lowest main cutting force was found to be 538 N and the lowest average surface roughness, 0.755 mu m, both at 100 m/min with a multicoated cemented-carbide insert KC9240, whose top layer is coated by TiN. Moreover, the experimental results indicated that the CVD cutting tools performed better than the PVD and the uncoated cutting tools when turning the Hastelloy X in terms of the surface quality and the cutting forces with the current parameters.