The study investigates on temperature distribution of moving heat source performed on a coupon. Heat dissipation and penetrationcharacteristics are being investigated. Finite element solution of a moving heat source model is attempted by using ANSYS. Transient thermal analysis model was chosen to achieve heat input characteristics for the model. Volume of welding process, voltage and current were the parameters considered in designing the heat source. Heat source was formulated using Gaussian heat equation. The heat source was introduced on plates of different thicknesses (3mm, 4mm, 5mm and 8mm) and was found that the heat dissipation characteristics changed in accordance with the thickness of the coupons. The study suggests that the trial welds and bead on welds should be done on samples with similar thicknesses as it directly affects the metallurgical characteristics of the weld.