Cutting-Tool Materials and Cutting Fluids

The reasons for the availability of a large variety of cutting-tool materials is best appreciated by reviewing the top eight parameters in the first column in Table 22.2 on p. 638. Among various factors, the type of workpiece material machined, the type of operation, and the surface finish and dimensional accuracy required all affect the choice of a cutting-tool material. For example, for interrupted cutting operations such as milling, we need toughness and impact strength. For operations where much heat is generated due, for example, to high cutting speeds, hot hardness is important. If very fine surface finish is desired, then materials such as ceramics and diamond would be highly desirable. These materials continue to be investigated further because, as in all other materials, there is much progress to be made for reasons such as to improve properties, extend their applications, develop new tool geometries, and reduce costs. The students are encouraged to comment further.