This document is a project proposal that investigates the effect of cooling media and hardening temperature on the physical properties of AISI D2 tool steel. The objectives are to study how cooling media and hardening temperature influence material hardness during heat treatment. Specimens of AISI D2 steel will be carburized and quenched at temperatures of 1000, 1020, and 1040°C, then cooled in different media like water, brine, ice, and oil. The literature review covers properties of D2 steel and previous studies on how heat treatment parameters affect hardness and microstructure. The methodology, schedule, and references are also outlined.