A common approach for the experimentally estimation of modal parameters is the Experimental Modal Analysis (EMA). EMA takes place in the standstill of the machine, consequently neglecting effects that only occur during the cutting process. Alternatively the Operational Modal Analysis (OMA) makes possible to investigate structures under operational loads and conditions. In this paper, a machine tool is investigated during cutting and the modal parameters are estimated by OMA, with several identification methods working in the frequency domain as well as in the time domain. These results are also contrasted to EMA to investigate the differences between cutting and standstill.