The industry-proven simulation tools of Diametal enable a depiction of the real conditions of the machining process. With this capability, typical sources of error can already be detected and eliminated during the design phase of a hob cutter: profile errors become a thing of the past. Expensive and time-consuming prototyping is rendered unnecessary. Diametal has been using these modern calculation methods in the construction of hobs for 15 years now. In addition, we are also able to model complete tooth profiles and create a full three-dimensional simulation of the milling geometry and the roll motion. This is carried out using mathematical models that have been developed by the construction designers at Diametal AG themselves and then integrated into state-of-the-art CAD simulation tools. All the milling tools that Diametal produces are systematically and completely modelled. It is only then that they are released for production.