A new plastic joining method of fixing bars with a hot forged plate is proposed. The bars at room temperature are directly joined to the high-temperature plate using a press. The optimum conditions of the proposed plastic joining method are examined using SCM435 bar and S45C plate on a mechanical press. By adjusting the indentation pressure to below the yield stress of the bar at room temperature during plastic joining, it is possible to attach the bar to the plate without buckling or fattening the bar. The bonding stress (shearing stress) between the bar and the plate is obtained in the range of 70-160 MPa depending on the die clearance, plate temperature or plate thickness. The bonding mechanism of the proposed plastic joining method is discussed from the viewpoints of adhesion of the bar-plate and the clamp stress associated with the thermal stress of the plate.