Tool failure is rarely a catastrophic break; it is usually a gradual wear process. The Taylor’s Tool Life Equation ($VT^n = C$) is a central concept in this volume.
The most widely available version is the Third or Fourth Edition published by McGraw-Hill Education India. manufacturing technology volume 2 - P.N Rao
Note: Ensure you are buying Volume 2: Metal Cutting and Machine Tools. Do not confuse it with Volume 1 (Foundry, Forging, Welding). Tool failure is rarely a catastrophic break; it
Given that gears are fundamental to machine drives, Rao devotes a full section to gear cutting: Note: Ensure you are buying Volume 2: Metal