A Switched Reluctance Motor (SRM) is a type of electric motor that operates on the principle of reluctance. Unlike conventional electric motors, SRMs do not have a permanent magnet or a wound field on the rotor. However, SRMs also have some disadvantages as high torque ripple and big acoustic noise. The three-phase SRM torque ripple is affected by electromagnetic torque harmonic orders which is difficult to estimate due to a highly nonlinear flux-linkage magnetic characteristic. Flux-linkage characteristic is a key SRM torque performance that depends on the stator/rotor pole structure. In this paper, torque and harmonic torque of SRM 6/4, 30kW is considered by the change of the stator/rotor pole arcs. The variation of average torque and harmonic amplitude torque with rotor pole arc in each SRM configuration is different. The finite element analysis results indicate the harmonic torque of SRM three phase 6/4 has mainly harmonic 3rd, 6th, 9th, 12th, and 15th which is a multiple of three phases of the stator winding. When gradually increasing the stator/rotor pole arcs, the torque does not increase linearly but exhibits nonlinearity. The torque reaches its maximum value at a stator pole arc of 300 and a rotor pole arc of 320. Additionally, at this pair of stator and rotor pole angles, the amplitude of torque harmonic waves is minimized, resulting in the least amount of torque ripple