Abstract: A method for detecting at least one tool state of a tool of a machine tool for machining workpieces, which includes at least one tool holder, at least one positioning drive, which includes at least one tool which is arrangeable or arranged rotationally fixed in the tool holder and which includes at least one control unit. The method includes the following steps: detecting or providing tool and/or workpiece data in the storage means and/or the control unit; providing at least one reference drive frequency of the rotary drive and/or the positioning drive; detecting at least one ACTUAL driving frequency of the rotary drive and/or the positioning drive; assigning the ACTUAL drive frequency of a reference drive frequency of the rotary drive and/or the positioning drive by the control unit and evaluating and/or interpreting at least the reference drive frequency associated with the ACTUAL drive frequency by the control unit.

Abstract: A numerically controlled machine tool controls the movement of a tool relative to a workpiece along a commanded path to cut the workpiece and to detect a load on the tool or workpiece. A specified position or section on the commanded path is the point at which the load on the tool or workpiece is detected and stored. Subsequently, the load on the tool or workpiece is detected each time the tool passes through the specified position or section and this detected value is compared with the above stored content. When the difference is larger than a predetermined value, an alarm signal is produced to indicate that the tool has worn out.