An equivalent model and electromechanical characteristics for the disk motor was obtained based on the Steinmetz parameters. This paper describes a series of tests conducted on an axial flux motor, equipped with an aluminum rotor disc and an YBCO high temperature superconducting rotor disc, at liquid nitrogen temperature (77 K). The rotating magnetic field was produced by a four-pole, three-phase stator winding, at 50 Hz. At asynchronous permanent regime, Steinmetz-type models are able to describe both motors' behavior. From the performed tests, the parameters of both motors' models were deduced. A variable load was used to obtain both motor's characteristics (conventional and superconducting). Experimental obtained characteristics of both motors are compared with the ones predicted from parameters' calculation. The HTS motor provides high efficiency then the conventional ones.