The maximum shear stress in a solid round bar of diameter, d, due to an applied torque, T, is given by Tmax 16T (d) A round, cold-drawn 1018 steel rod is subjected to a mean torsional load of T = 1.5 kNm with a standard deviation of 240 N-m. The rod material has a mean shear yield strength of Sy 312 MPa with a standard deviation is 30 MPa. Assuming the strength and load have normal distributions, what value of the design factor fa corresponds to a reliability of 0.99 against yielding? Determine the corresponding diameter of the rod. The design factor is The diameter of the rod is mm.