A major cause of invalid fatigue data is unintended bending. ASTM E466-15 mandates a strain-gage alignment check to ensure that bending strain does not exceed 5% of the axial strain.
This practice covers the following:
is the definitive guide for performing axial, force‑controlled, constant amplitude fatigue tests on metals. Following this standard ensures repeatable, comparable, and technically sound fatigue data. For any engineer or laboratory generating S‑N curves for design or quality assurance, obtaining the official PDF from ASTM is a necessary investment. astm e466-15 pdf