Austempered ductile cast iron (ADI) has emerged as an important engineering material in recent years because of its attractive properties. These include good ductility at high strength, high fatigue strength and fracture toughness and superior wear resistance.ADI has been widely used for various kinds of engineering components, such as gears, crankshaft, vehicle components, sprockets, cutting and digging tools etc. Also manufacturing of complex shapes with better surface finish, precise tolerances and higher production rates in such materials by traditional methods is even more difficult. This book pertains the influence of autstenitizing temperature on mechanical properties of austempered ductile iron. The effect of austenitizing temperature was examined by austenitized the tensile specimens at various temperature ranges.The microstructures characterized through optical microscopy and X-ray diffraction.