Cutting Tool Life in Machining at Various Speeds

Cutting tool life is usually described by means of the well-known Taylor formula, which originally specifies tool life as a function of cutting speed. That cutting is performed with the same tool at various successive speeds, thereby rendering the Taylor formula is unusable, which is a common problem. In the case of periodically changing cutting speeds it can be verified both theoretically and through experiments that equation Σ∆ti/Ti≈1 is valid. The generalised form of the Taylor formula, which can also be applied for cutting at periodically changing speeds, could be derived from this equation. If cutting is performed at various speeds, an equivalent speed and a corresponding tool life, which can also be handled by means of the traditional Taylor formula, may be specified.