This research aims to analyse the effect of preheating treatment on the toughness of welding results between carbon steel AISI 1037 and stainless steel AISI 304 using shield metal arch welding. The temperatures used are non, 150oC, 200oC, 250oC and 300oC with preheating treatment time of 15 minutes/temperature. From the charpy impact test, it was found that the energy absorbed by the material w…