In modern manufacturing processes, machine tools are indispensable equipment. They are mainly used in the automotive industry, mechanical engineering and drive technology. In practice, the machine tool industry is often divided into two main fields: metal forming and metal processing. Inductive proximity switches with high protection levels against corrosive coolants can precisely detect the positions of workpieces, workpiece carriers, and mechanical components. The fault diagnosis system and vibration sensors can achieve condition-based maintenance, capable of detecting unbalance, wear or bearing damage in the spindle and drive unit, thereby preventing production losses, downtime due to faults and costly indirect damage. Visual sensors can reliably detect the quality of components and workpieces. In a machining center, flexible production systems, conveyor lines and code readers can ensure the traceability of components. The flow meter continuously monitors the consumption of water and compressed air, thereby significantly improving energy efficiency. Among these sensors, many of them can communicate with the high-level controller via IO-Link. This means that users are already ready for Industry 4.0.