This chapter reviews various specific purpose materials (SPMs) and their applications. In specific, NiTi alloys are considered in this study because of their numerous applications in the biomedical, automotive, microelectrical and electronic component fields. The elemental additions to NiTi alloy and their influences on various properties are also detailed and reviewed. The NiTi alloys manufactured by using various strategies have their own advantages, defects and dimensional accuracy values, which are evaluated, reported and studied. The process of converting NiTi alloys into the required parts, such as sheets and rods, among others, is also reported and reviewed. The application of machining NiTi alloys and their advantages and disadvantages are studied. Electric discharge machining, laser machining and conventional microdrilling are reviewed. Finally, the electrochemical corrosion behaviour of NiTi alloys is reviewed.