The impact of aluminum and manganese in different proportions on the mechanical properties of brass was investigated. Aluminum (Al) and Manganese (Mn) are examples of metals that are soluble in brass whose proportion in brass can be optimized to obtain desirable characteristics. Fifteen different samples were investigated ranging from the pure brass (red brass), 1-10 % Al in brass and 1-10%Mn in brass respectively. Standard specimen preparation methods were employed and mechanical properties such as tensile strength, impact strength and hardness were carried out using Mosanto tensometer and Izod testing machines. Results obtained showed that the mechanical properties of brass improved for 5 % increase in aluminum and manganese proportions and above 5 % aluminum and manganese proportions a decrease in the mechanical properties was noticed. This was due to compositional impact of properties of brass.