In other words, everything is OK. Melanie nods and presses the Start button. A chamfer milling machine approaches a gleaming metal block, cutting through its surface in an almost effortless motion. Shavings fly in all directions. A component is coming to life that will feature numerous bevels, boreholes and edges. Two hours later, the machine's work is done and Melanie is still in her element. She uses an altimeter to inspect various points on the ring, documenting her results in the measurement report.

She repositions the sizeable ring in the CNC center, then makes a correction here and performs a check there. Three repetitions later, she's happy. There are 34 measuring points within the tolerances. Very strict tolerances. That's because this metal ring is destined to form part of a highly sophisticated and precise ZEISS product: the latest-generation EUV optic. ZEISS' partner ASML will integrate these optics into their lithography systems. These machines use extreme ultraviolet light (EUV) at a wavelength of precisely 13.5 nanometers to expose photoresist-coated silicon slices (wafers). This creates nanofine structures that contain several billion transistors per square centimeter. But, that will only work if Melanie's metal ring can deliver the utmost precision. And the ring – crafted by this trained metal cutting engineer, does just that.