In this experiment, the dimensional accuracy and roundness of 25 holes were measured during repeated processing using one circular pocket tool under different cutting conditions, such as various feed rates and spindle rotation speeds, using A6061-T6 material and TiCN- and TiAlN-coated end-mill tools. The purpose of this analysis is to determine the optimal cutting conditions. As a result of measuring the surface roughness, it was found that the TiCN-coated tool exhibited the most precise dimensional tolerance at a spindle speed of 2,000 rpm and feed speed of 200 mm/min, which corresponded to an Ra value of 0.4583 µm. Moreover, TiAlN-coated tools showed the tightest dimensional tolerances at a spindle speed of 3,000 rpm and feed rate of 100 mm/min. As a result of measuring the straightness, it was found that the TiCN-coated tool showed the most precise straightness at a spindle speed of 3,000 rpm and feed speed of 100 mm/min. When the maximum and minimum dimensions of the surface roughness of each coating tool were compared, the TiCN tools were found to be more favorable. However, when the minimum and maximum dimensions of straightness were compared, the TiAlN tools were found to be more favorable.