Electrical discharge machining (EDM) is one of non-traditional methods employed to produce complicated forms of electrical conductive materials. This process can be applied to materials difficult to machine with traditional methods. Thus, the study and analysis of EDM variables play an important role to improve the yield, and safety of a surface. This research aims at study and analyze influence of pulse current (Ip) (10, 16, 22) Amp, pulse on time (Ton) (50, 100,150) μs and pulse off time (Toff) (25, 50, 75) μs, (keeping other parameters fixed) on a Recast Layer Thickness (RLT) for machining (AISI 1018 mild carbon steel) using Response Surface Methodology (RSM) within “Minitab 17” for designing of experiments. Optical microscopy and scanning electron microscopy (SEM) was used. Experiments proved that minimum RLT was 5.2 μm at Ip, Ton and Toff at 10Amp, 50 μs and75 μs, respectively. The results also indicated that RLT increased with the increased (Ip and Ton) and decreased in Toff.