Archive for the “Machinery” Category

ANALYSIS OF A CRACKED SPLINED COUPLING Summary: A fractured spline gear coupling was received for analysis to investigate the cause of failure. Results indicated the coupling fractured in fatigue, initiated at the bottom corner of the keyway from the ID of the coupling. The keyway exhibited significant yielding which widened the keyway, indicating the strength […]

  Failure Analysis of Fractured Tool Steel Die Plate Summary: A cracked polymer filament die plate was received for analysis to determine the cause of cracking. Results indicate the die plate cracked as a result of a brittle nitrided case and an insufficient cross-sectional area of the narrow ligament between the cap screw hole and […]

Failure Analysis of Arcing and Contact Fatigue of Ball Bearings Summary: The four seized bearings submitted for metallurgical analysis were determined to have suffered deterioration of their grease to the point that it was inhibiting motion rather than enabling. The grease had turned to a thick (viscous) black sludge that was full of particulate. Electrical […]