Within a short period of time, a blank is transformed into a wheel with teeth that a layperson may even believe to be finished. However, in this state, the teeth would only last a few hours when in operation as they are subject to enormous strain in the engine. The gearwheels are not made really robust until they are exposed to temperatures over 900 degrees, purposefully enhancing the edges using carbon and quenching the steel in an oil bath. The soft material – which may be altered as a result – is hardened.
Following heat treatment, the precision work is completed on the hard machining line. "The requirements for the gearwheel only allow tolerances of up to a few thousandths of a millimeter. Everything must fit together," says the shift supervisor, Andreas Drach. The gearwheels are then once more placed on a conveyor belt that is approximately 12 meters long. In turn, the gearwheels are processed on a hard turning machine, a gear grinder and a continuous washing machine. After being checked for cracks and finished off with a bearing bushing if necessary, the wheels are ready for packaging. They are then stored in the "supermarket" that directly supplies the consumer.