tough-absorbing bits for hard materials e. G. Sheet steel or metal. In this case the screw initially turns smoothly inside the defined thread. As soon as the head of the screw touches the material surface, high torque peaks are generated that have an effect on the screw and tool. This can mean that the bit breaks if it is too hard. Tough-absorbing wera bits prevent any premature breakage of the drive tip. Recognisable in the catalogue through the article letter z.