This is more of a theoretical question. Not sure if this should be under this section or Mechanical Engineering. 1. The problem statement, all variables and given/known data For 1018 steel, I tested the UTS to be about 83 ksi for a dogbone specimen with a circular cross-section. However, when I determined the Ultimate Bending Stress from a 3 point bend test with 1018 steel cylindrical bar, the Ultimate bending stess was 204 ksi. I've noticed the same differences in stress at the yield point. 73 ksi for tensile yield and 152ksi for bending yield. I got similar values when running an FEA. These values I got were what I was expected on seeing. I am just wondering why the stresses from a bending and tensile test vary so much? Bending fails in tension. They both also have the same fracture surface, microid covalesence. Can anyone explain why there is a difference or recommend references? Thanks! 2. Relevant equations stress = force/area stress = Mc/I 3. The attempt at a solution Is some of the load absorbed by the compression component of bending? Accuracy of equations? Mc/I is for elastic only.