The austempered cast iron (ADI - Austempered Ductile Iron), has been successfully applied in diesel trucks, class 8 trucks and agricultural tractors power train parts. This material has also been used in high performance gears, applied in various segments of the mechanical industry, especially in the automotive field because of their properties and technical advantages associated to the combination of strength and ductility of the material. The main technical limitation of the ADI is attributed to its machinability. This problem is related to the hardening that occurs by the transformation of austenite, characteristic of the microstructure of austempered ductile, which affects the steps of the production process and achieve common cropping the part before the heat treatment and finish machining right after them. This paper discusses a study on the behavior of the surface finish quality, technical and financial feasibility of the machining process. Comparing the use of grinding, CBN wheel, and the hard turning operation, cemented carbide coated TiAlCrN, of ADI by comparative analysis of lifetime of the tools in terms of speed of cutting, using as a criterion to end the life of the tool flank wear of 0.3 mm.