Collective transverse momentum flow of nucleons and fragments in intermediate energy Ar40+27Al collisions is calculated with the antisymmetrized molecular dynamics (AMD). The observed flow and its balance energy are reproduced well by calculation with the Gogny force which corresponds to the soft equation of state (EOS) of nuclear matter. The calculated absolute value of the fragment flow is larger than that of the nucleon flow in the negative flow region, which can be explained by the existence of two components of flow. In addition to many similarities, the difference in the deuteron flow is found between C12+12C and Ar40+27Al collisions, and its origin is investigated by studying the production mechanism of light fragments. We also investigate the dependence of the flow of nucleons and fragments on the stochastic collision cross section and the effective interaction, and conclude that the stiff EOS without momentum dependence of the mean field is not consistent with the experimental data.