A method for monitoring a tool clamping system of a work spindle of a numerically controlled machine tool having a control device for controlling machining of a workpiece with a tool clamped on the work spindle by means of a tool interface, if a tool is clamped on the tool interface receptacle of the work spindle by means of a tool interface, wherein said work spindle has a plurality of force sensors (142a, 142b) on bearing surfaces of a tool interface receptacle of the work spindle and sensor values of the force sensors (142a, 142b) of the work spindle are provided on the control device when the tool is clamped by means of the tool interface on the tool interface receptacle of the work spindle, said method comprising: - determining a force distribution on the bearing surfaces of the tool interface receptacle when the tool is clamped by means of the tool interface on the tool interface receptacle of the work spindle on the basis of the sensor values provided by the force sensors (142a, 142b), and - monitoring the tool clamping system of the work spindle when the tool is clamped on the tool interface receptacle of the work spindle by means of the tool interface at the control device on the basis of the force distribution determined, in particular with regard to the requirement to carry out safety control measures to protect against spindle damage, workpiece damage and/or tool damage during workpiece machining characterized by - determining a position of one or more interfering objects which influence the clamping situation and are present between bearing surfaces of the tool interface receptacle and corresponding bearing surfaces of the tool interface of the clamped tool on the basis of the determined force distribution when it is determined on the basis of the determined force distribution that one or more interfering objects influencing the clamping situation are present between bearing surfaces of the tool interface receptacle and corresponding bearing surfaces of the tool interface of the clamped tool. wherein said work spindle has a plurality of force sensors (142a, 142b) on bearing surfaces of a tool interface receptacle of the work spindle and sensor values of the force sensors (142a, 142b) of the work spindle are provided on the control device when the tool is clamped by means of the tool interface on the tool interface receptacle of the work spindle, said method comprising: - determining a force distribution on the bearing surfaces of the tool interface receptacle when the tool is clamped by means of the tool interface on the tool interface receptacle of the work spindle on the basis of the sensor values provided by the force sensors (142a, 142b), and - monitoring the tool clamping system of the work spindle when the tool is clamped on the tool interface receptacle of the work spindle by means of the tool interface at the control device on the basis of the force distribution determined, in particular with regard to the requirement to carry out safety control measures to protect against spindle damage, workpiece damage and/or tool damage during workpiece machining - determining a force distribution on the bearing surfaces of the tool interface receptacle when the tool is clamped by means of the tool interface on the tool interface receptacle of the work spindle on the basis of the sensor values provided by the force sensors (142a, 142b), and - monitoring the tool clamping system of the work spindle when the tool is clamped on the tool interface receptacle of the work spindle by means of the tool interface at the control device on the basis of the force distribution determined, in particular with regard to the requirement to carry out safety control measures to protect against spindle damage, workpiece damage and/or tool damage during workpiece machining characterized by - determining a position of one or more interfering objects which influence the clamping situation and are present between bearing surfaces of the tool interface receptacle and corresponding bearing surfaces of the tool interface of the clamped tool on the basis of the determined force distribution when it is determined on the basis of the determined force distribution that one or more interfering objects influencing the clamping situation are present between bearing surfaces of the tool interface receptacle and corresponding bearing surfaces of the tool interface of the clamped tool. - determining a position of one or more interfering objects which influence the clamping situation and are present between bearing surfaces of the tool interface receptacle and corresponding bearing surfaces of the tool interface of the clamped tool on the basis of the determined force distribution when it is determined on the basis of the determined force distribution that one or more interfering objects influencing the clamping situation are present between bearing surfaces of the tool interface receptacle and corresponding bearing surfaces of the tool interface of the clamped tool.