OWD, the "trick" here is in how carefully the thread roots at the terminis of the threaded section is handled. Any truly sharp corner can act as a stress riser when force is applied to the pin/ screw. The force will be shear as the set-up doesn't allow for the screw/pin to have axial tension beyond tightening torque and no compressive forces at all. "Vee" screw form threads are usually visualized as having a very sharp corner at the thread root/bottom and top. Standardized threads have a flats at the top and bottom of both male and female threads to mitigate stress risers.
DDA
