The first step is to sharpen to a new, constant angle of 15 or 20 degrees for the first time. Most knives come from the factory with a certain angle, between 15 and 20 degrees, but it's not always constant. Initial sharpening therefore takes between 2 and 6 minutes. For very hard special blades, such as Damascus, it can take up to 10 minutes. From the second use onwards, when the knife has become a little dull again, resharpening takes just a few back and forth movements, as the angle of sharpening is already given by the first resharpening.