Railway train squeal noise on a curve of small radius consists of specific frequencies which correspond to the natural frequencies of the axial vibration of a wheel. Those vibrational modes are nodal modes, such as (4,0) or (7,0), and the damping coefficients of a wheel are small in those particular kinds of modes. To investigate the specific frequencies of squeal noise, we made an experimental apparatus which has a thin steel disk and a steel rod. For the purpose of our experiment we will assume that the disk serves as a wheel and the rod serves as a rail. The circumferential face of the disk is rubbed in the axial direction with the rod. The frequencies of squeal noise generated by this fundamental experiment are coincident with those of the nodal modes. Frequencies with a small damping coefficient tend to occur in the squeal noise. Thus, the results of the numerical model concerning the main frequency of squeal noise generated by the coupled vibration of a disk and a rod almost agreed with the results of our experimental model.