Hard materials scratch soft ones – this insight forms the basis of all classic hardness testing methods. Whether Rockwell, Vickers, Brinell or modern methods such as UCI: they all leave marks on the workpiece. But there is another way. The QASS μmagnetic measuring system uses the magnetic Barkhausen effect to determine hardness without contact and without causing damage. This method opens up completely new, forward-looking possibilities for quality control in heat treatment and manufacturing, such as 100 % testing in series production.