This book is intended to provide concentrated information on the subject of torque wrenches. Torque wrenches have undergone a rapid development from simple tools to precise measuring tools. This is due to advanced mechanization, ever-improving manufacturing methods and optimization processes. While it was still possible to repair a motor vehicle with a set of wrenches in the 1970s, such an "intervention" today would be a blatant safety risk and probably also the technical end of an engine, for example. Torque wrenches have also become indispensable in the medical field. Dental implants, for example, are precisely placed and fastened with the smallest torques. Unfortunately, it can be observed that the landscape of standards and regulations - thought out and developed by experts - is often not, or only slightly, transported to the people who are supposed to implement the normative specifications. This book is intended as an introduction to the subject of torque wrenches, providing the user with basic knowledge and serving as a reference work and list of references and a usefull helper for torque wrench calibration issues.