In this paper, a new dry die-sinking EDM polishing method using a mouldable polymer composite electrode as tool is presented. This EDM method involves two new concepts, namely: dry die sinking and the polymer composite tool. An experimental investigation was performed on the dry die-sinking EDM process to assess the feasibility of finishing down to 0.2–0.3 μm Sa, and polishing from 0.2 to 0.3 μm Sa down to the finest achievable surface finish. To simplify sample preparation, the methodology involved a reversal of the polishing process. Hence, the surface finish of a 13-mm diameter P20 tool steel disk was taken from a lapped 0.01-μm Sa surface finish up to a rougher steady-state surface finish value, assuming comparable results with conventional rough-to-fine polishing procedures. Several process parameters were evaluated such as: pulse current level I EP , open-circuit voltage V OC , pulse time on T ON , pulse time off T OFF , number of polishing cycles N C and three pulse identification methods, for their effect on sample surface finish micrometre Sa, material removal rate MRR cubic millimetre per hour and electrode relative wear rate ERWR.