Furthermore, in the event of maintenance customers expect individual inserts to be replaced quickly and hassle-free. Here the experience of manufacturers who know the material behaviour of the individual plastics in detail really counts. Because the smallest divergence can have a negative impact on production. Tolerances are extremely fine: for instance, with tool sizes of 0.75 x 10 cm a maximum divergence of 0.02 mm is tolerated. In mould separation, it is under ten microns due to the high injection pressures; in the assembled state as little as just 5 μm. Manufacturers walk a fine line here and look to creating ideal production conditions. Workshops are fully air-conditioned and automatic probes are used to detect the zero points of the components directly in the machine to avoid deviations. Form accuracies are measured by tactile methods and documented on the milling machine. A periodic recalibration using a reference part previously measured externally serves as control. Simulations of the injection moulding process play an essential role in meeting customer demands for aesthetic and haptic concepts in the best possible way.