This thesis describes the work undertaken by the author in the development of tool life testing techniques.

The first and second chapters are devoted to a study of the turning process, the first chapter being a survey of the current state of knowledge, whilst the second chapter is mainly concerned with the development of the stress-temperature method of tool life testing.

The third chapter is devoted to the milling process and deals mainly with the process of peripheral milling. Because of the inherent complexity and lack of knowledge of the milling process, then the work described in this chapter is aimed at a basic understanding of the influences of mechanical and thermal shock and a varying feedrate on cutter wear rates.

The fourth chapter discusses methods of supplying machining data to industry, with particular emphasis upon the development of machining data handbooks which has been carried out by the author.