This study aims to determine the effect of Asem wood charcoal in the heat treatment process using the carburizing method on SS 400 steel on mechanical properties and microstructure.In this study, the carburizing medium used was tamarind wood charcoal with a weight percentage of 60% and a CaCo3 catalyst of 40%. The temperature used is 8500C with a holding time of 60 minutes with a variation of 15w-40 oil and water quenching media.The results of the tensile test show that the carburizing material with variations of oil and water quenching media has more brittle properties than the raw material. The surface hardness value for raw material is 191.53 VHN, while for carburizing material with oil quenching media it is 412.00 VHN, while for carburizing material with water quenching media it is 508.64 VHN. The results of micro photos of carburizing material with water quenching media have a pearlite phase which is more dominant than raw material and carburizing material with oil quenching media
