|
Clevis
Pin Failure
A turnbuckle clevis pin used to hoist and hold the mast of a
sail boat in place failed, resulting in the mast
falling into the ocean. A metallurgical failure
analysis was requested on the failed turnbuckle pin.
Metallurgical testing included
macro/microphotography,
EDS analysis, and scanning
electron microscopy (SEM).
Upon examination, the subject fractured turnbuckle
clevis pin was found to contain massive amounts of interdendrite
casting porosity. This interdendrite casting
porosity was the result of insufficient liquid feed
metal into the casting mold during the casting process. In addition, the
chemical composition of the subject turnbuckle
clevis pin was not of marine quality bronze.
Photograph A: Overall view of the subject failed turnbuckle and fractured clevis pin.
Back to top
|
Dr.
R. Craig Jerner, Ph.D., PE specializes in accident
investigation and metallurgical failure analysis,
with over 30 years experience as a metallurgical
consultant and accident investigator. He has
testified as a metallurgical expert in over 250
depositions and more than 70 court appearances. If you or someone you know should need the services of Dr. Jerner and J.E.I. Metallurgical, please visit our web site at the buttons below, or e-mail Dr. Jerner --- 