Failure analysis expert witness performed a failure analysis on a broken grinding wheel. This is part of a product liability case where it was claimed that the wheel broke apart during normal use and injured the user. Examination of the wheel showed that the wheel had been broken by someone clamping it and breaking off a piece. The upper left photograph shows the failed wheel. this wheel has the paper label bent over. This indicates that the wheel did not spontaneously fail. Upper right is a photomicrograph of the paper label opposite the break. Visible is a linear array of marks indicating that this wheel had been held in a clamp (such as a vice). This evidence shows that the subject grinding wheel did not fail spontaneously as described by the injured user. There was no product defect or manufacturing defect with respect to this wheel.