In this research, an investigation was done to determine why Impact Energy decreases after tempering above 200C. The goal is to evaluate how tempering conditions effect the microstructure and mechanical properties of the two alloy PM steels FLN2-4405 and FD-0205. The mechanical properties being analyzed are Impact Energy, Transverse Rupture Strength, Microhardness, and Dimensional Change. The microstructure and mechanical properties will be related to see the effect the tempering conditions have on the materials.