Machinability of Metals by Orlan W. Boston explores methods to designate the machinability of metals. The text outlines various ways to measure machinability, including force on the tool, power required, tool life, surface finish, drill penetration, drill torque, cutting speed, hardness numbers, and heat generated. The study discusses challenges in defining machinability and the need for standardized conditions. The author reviews existing research, highlighting the variability in results and the complexity of metal cutting processes. The text aims to provide a comprehensive understanding of machinability, offering data and methodologies used by various researchers to assess metal cutting resistance, tool performance, and material properties.