This work pack carburized mild steel test specimens with locally sourced bone charcoal, coal and wood charcoal, hardened and tested the specimens for hardness, impact and tensile strengths. Moderating effect of time was investigated at one hour, two hours, three hours, four hours and five hours carburising times. Direct testing and measurements of hardened specimens on appropriate testing machines showed that: coal, wood charcoal and bone charcoal increased both hardness and tensile strength of mild steel but decreased the impact strength; wood charcoal had the greatest hardening effect on...