Pre-machining of gear wheels is often done by hobbing using a soft work-piece material. Today, almost all of the hobs are used with a hard coating to enhance their life-time considerably. This paper describes the results obtained with a tailored coating in a single tooth cutting test (fly cutting). We show that a nano-structured multi-layer coating based on AlCrN is able to protect a tool better than conventional single-layer coatings. The specific mechanical and structural properties of the coating are explained in detail.