From section 3–12, the maximum shear stress in a solid round bar of diameter, d, due to an applied torque, t, is given by   3 16 / .   max  t d a round, cold-drawn 1018 steel rod is subjected to a mean torsional load of t=1.5 kn ? m with a standard deviation of 145 n • m. the rod material has a mean shear yield strength of ssy  312 mpa with a standard deviation of 23.5 mpa. assuming the strength and load have normal distributions, what value of the design factor nd corresponds to a reliability of 0.99 against yielding? determine the corresponding diameter of the rod.