This article discusses the factors to be considered in selecting and evaluating machining tests for the purpose of evaluating cutting tool performance and workpiece machinability. It provides a brief description of cutting tool materials, such as high-speed steels, uncoated and coated carbides, cermets, ceramics, cubic boron nitride, and polycrystalline diamond. The article considers the matrices that represent the range of tests performed on candidate cutting tool materials: the workpiece matrix, the property matrix, and the operation matrix. Various machine tests used to evaluate cutting tools, including the impact test, turning test, and facing test, are described. The article lists the factors to be taken into consideration in measuring the machinability of a material. The article presents general recommendations for proper chip groove selection on carbide tools and concludes with information on machining economics.