This research aims to investigate the benefits of using the milling process to refurbish worn hot forging dies made from JIS SKD61 tool steel. The milling process is categorized into rough milling, semi-finish milling, and finish milling, and is compared to the production of new dies in terms of production cost. The production cost is estimated based on the quantity of cutting tools used, the number of machining hours, and the cost of work materials required for manufacturing new dies. Experimental results, obtained using reverse engineering technology to examine dimensional damage on die surfaces, revealed that the maximum deviation of the worn die surface from the original model was 1.932 mm. Therefore, a minimum milling depth of 10 mm is required to completely remove the worn surface. Analysis using a Computer Aided Manufacturing (CAM) program showed that the volume of material removed during die refurbishment was 26.67% less than machining new dies. However, the machining time for refurbishing the worn die was approximately 3.44% longer than for producing a new one. This is because the original shape of the work model leaded to CAM generated different tool path for the rough milling. The reformed die being machined from material with already enhanced mechanical properties required more cutting tool compared to new die production. Despite this, the overall production cost of refurbishing a worn die was approximately 43.47% lower than a new one when work material of tool steel was considered.