Abrasive Processes are usually among the most expensive as they are they are generally quite slow.� However, they can machine extremely hard surfaces, and can be used on materials that are beyond the limits of virtually all other traditional machining processes.� Moreover, because they are so slow (ie because the material removal rate is so low and the chip size is so fine) they have extreme precision and produce excellent surface finishes-- is essence beyond those of any other manufacturing process.� (Maybe a few� exotic manufacturing processes that work on the atomic level have better finish and precision, but you will not be using these when working with tool steel.)� For this reason the abrasive processes are quite common, especially in tool and die work (often have hard materials, or need for high precision/surface finish).