Fastening screws used in fuel-injection pumps failed during assembly and were examined to determine the cause. Based on observations and the result SEM fractography and hardness measurements, the screws failed by brittle intergranular fracture due to hydrogen embrittlement associated with plating procedures. The report includes recommendations for improving the quality of the screws.

During cyclic spin tests, the turbine disc in an aircraft engine broke apart with a loud noise, followed by a fire. Based on a detailed examination and the results of SEM fractography and hardness measurements, failure analysts concluded that a locking plate became dislodged due to the shearing of the screws that hold it in place. They also provided recommendations to remediate the problem.