Additional info: visually and dimensionally confirmed the instrument is broken at the base of the radius near the 70 mark.No surface defect identified that could contribute to crack propagation.Dimensional inspection of the relevant dimensions, as well as the instrument hardness were inspected and found to be within print specification.Microscopic examination of the fracture surface finds a fairly brittle fracture with no indication of torsion or fatigue, and river lines suggesting the direction of propagation.The location and fractographic evidence of the fracture surface, in conjunction with verification of conformance to the relevant dimensional and material specifications suggest failure due to bend stress overload.The above observations are consistent with bend stress overload.
|