In robotic machining applications, the precision of the robot is of great importance. In heavy machining process, the lower stiffness of industrial robots results in greater position errors than that of the CNC machine executing the same process. In this contribution, a new stiffness model with 36 degrees of freedom and nonlinear descriptions are presented together with a new identi cation method. Experimental results outline the potential of the model in machining application. Acknowledgment: The authors would like to acknowledge Mr. Justus Kopp and Mr. Julian Ricardo Diaz Posada at Fraunhofer IPA for taking part in the laboratory experiments and the implementation