What was found
(CAN) ACFT NR 1 PROP HUB WAS GOING TO BE REMOVED DUE TO AN OIL LEAK WHEN IT WAS DISCOVERED SEVERAL OF THE PROP HUB ATTACH NUTS WERE LOOSE & OR CRACKED. THE PROP HUB WAS ONLY INSTALLED FOR APPROX 202 HRS. THE HUB HAD PREVIOUSLY BEEN SENT TO A REPAIR SHOP & RETURNED WITH NEW PROPELLER SECURING NUTS. ATTACHED ARE PICTURES OF THE HARDWARE IN QUESTION, PN 784776-. UPON FINDING THESE ISSUES WITH THE CRACKED NUTS OUR PERSONNEL COMPARED THE CRACKED NUTS TO OTHER EXAMPLES OF SERVICEABLE PROPELLER NUTS & WERE SURPRISED TO NOTE THE NUTS LOOKED SIMILAR, BUT WERE IN FACT DIFFERENT THAN THE OTHER EXAMPLES OF PN 784776-1. THE CRACKING NUTS APPEAR TO NOT BE AS WELL DEFINED OR HAVE AS SMOOTH FINISH AS THE SAMPLE OF A GOOD NUT. OUR IMMEDIATE ACTION WAS TO QUARANTINE & REPLACE THE SUSPECT NUTS FROM THE PROPELLER. THEN INITIATE AN IMMEDIATE FLEET CAMPAIGN TO VISUALLY INSPECT, TO TRY & LOCATE FURTHER SUSPECT NUTS & RE-TORQUE, TO CHECK FOR SECURITY. ALL PROPELLER SECURING NUTS WITHIN OUR FLEET.