A steel rod AISI 1040 has the ultimate tensile strength Sut of 113 kpsi. Determine the rotating bending specimen's endurance limit S'e at 10 to the 6th cycles.
A rule of thumb for endurance limits of steel with Sut 200 ksi is that S'e = 0.504 x Sut, thus for your case that would be 113 x .504 = 56.95 ksi (endurance limit is defined as fatigue life greater than 10^6 cycles)
