As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON RE-ASSEMBLY OF A 43E60-583 PROPELLER, THE TORQUE SEQUENCE OF THE BARREL BOLTS WAS BEING ACCOMPLISHED AS PER CANADAIR MAINTENANCE MANUAL SUPPLEMENT 61-10-51. WHEN TORQING ONE OF THE BARREL BOLTS P/N 72429, THE HEAD SHEARED OFF OF THE BOLT SHANK JUST AS MAXIMUM TORQUE WAS BEING REACHED. IT WAS OBSERVED THAT THE WEIGHT INSERT IN THE MIDDLE OF THE BOLT WAS CORRODED AND COULD BE THE CAUSE OF THE HEAD SHEARING.