Manufacturing companies define the qualities of thermal removing process based on the dimension and physical appearance of the cutting material surface. The surface roughness of the cutting area for the material and the material removal rate being removed during the manual plasma arc cutting process were importantly considered. Plasma arc cutter machine model PS-100 was used to cut aluminum alloy 1100 manually based on the selected parameters setting. Two different thicknesses of specimens with 3 mm and 6 mm were used. The material removal rate (MRR) was measured by determining the weight of the specimens before and after the cutting process. The surface roughness (Ra) measured by MITUTOYO CS-3100 device. Taguchi method was utilized as an experimental layout to obtain MRR and Ra values. With lager the better condition of Signal to Noise Ratio (S/N) ratio, the percentage contribution of Material Removal Rate at 3 mm maximum 69.55% and minimum 4.08% value. While, contribution of Material Removal Rate at 6 mm is maximum 80.2 % for obtaining and minimum 11.8%. However, with smaller the better condition of S/N ratio, the percentage contribution of surface roughness for 3 mm is maximum 23.4%, and minimum 11.0%, while, the percentage contribution of surface roughness for 6 mm is maximum 56.6%, and minimum 7.6%. The results indicate that the current and cutting speed is the most significant parameters, followed by the arc gap for both rate of material removal and surface roughness.
