Three bolts are used in the connection shown in the figure. The thickness of plate (1) is 15 mm. The ultimate shear strength of the bolts is 345 MPa, and the ultimate bearing strength of plate (1) is 305 MPa. Determine the minimum bolt diameter required to support an applied load of P = 155 kN if a minimum factor of safety of 2.0 is required with respect to both bolt shear and plate bearing failure.