The device "F" shown in the illustration is best used to __________. GS-0080

Correct Answer: Option C — assist in securing a coupling half to its shaft

Device F is a headless set screw with a dog point, specifically designed to seat into a pre-drilled hole or keyway on a shaft. This ensures precise alignment and positive locking of a coupling half, preventing axial or rotational movement under the high torque loads common in marine propulsion.