The patented KX 500 FLEX is designed for the flexible use of a wide range of tooling and machining technologies. Thus, application-specific production solutions can be configured to perform diverse processing jobs and a wide range of batch sizes efficiently and economically. Dressable tools for versatile machining processes and non-dressable CBN tools can be used for highly productive manufacturing as well as grinding of gear geometry with interfering edges. The machine concept is based on a rotary indexing table which incorporates the tailstock and dresser offset against the workpiece spindle. The dressing unit can accommodate a single or twin spindle dresser. Due to the use of auxiliary spindles small grinding wheels can be applied. Both involute internal gears and special profiles can be machined with the internal grinding device.