The development of flexible automation in the manufacturing industry is concerned with production activities performed by unmanned machining systems. A major topic relevant to metal-cutting operations is monitoring tool wear, which affects process efficiency and product quality, and implementing automatic tool replacements. In this paper, the measurement of the cutting force components has been found to provide a method for an in-process detection of tool wear. Cutting force components are divided into static and dynamic components in this paper. The static components of cutting force have been used to detect flank wear and the dynamic components of cutting force have been analysed to detect crater wear. To eliminate the influence of variations in cutting conditions, tools, and workpiece materials, the relationships between normalized cutting forces and cutting conditions are established. According to the proposed method, the static and dynamic force components could provide the effective means to detect flank and crater wear for varying cutting conditions in turning operation.