A new apparatus was designed to measure the electromagnetic force and a computational study of the traveling magnetic field (TMF) and its application to the Ga-In-Sn melt (with low melting point), then the forces on Al, Mg, and Li melt, were simulated. The result show that the electromagnetic force on the melt increases linearly with the increasing length of the melt in the TMF. The TMF-induced Lorentz force increases with increasing frequency, and then decreases. The maximum value is obtained when the current frequency is 160 Hz, over that frequency the force decreases rapidly. When the iron-core is activated, the force increases when the melt closes to the iron-core. The Lorentz forces have inversely-proportional relationships with the electrical resistivity, the d-x/dρ decreases and the d-y/dρ increases with the increasing electrical resistivity (d-/dρ is the slope of the Lorentz force profile).