Hi Guys and Gals,

Probably I'm just being paranoid but maybe more people experienced this:
One of the motors on my brand new P3A has a slightly awkward thread resulting on the prop not going on smoothly like the others.
Normally you give them a swing and they'll wind on by themselves, not so on this one. It needs to be done manually all the way with very slight resistance.
There is a minor 'bulge' at the top on the thread. Once the prop is on it is tight as a mofo, so I am not concerned it coming off any time soon.
What I am concerned with is that after many attach/detach cycles the thread in the prop may wear out resulting in a crash.

Should I be worried?

It looks OK but I would get it replaced.  The hubs are plastic composite and extra wear and tear might lead to an loose prop which could pop off in an aggressive breaking (err braking) maneuver.  Not worth the worry about it.

It shouldn't make any difference because of the way threads work.  Even worn & very loose threads will still tighten properly.  It's the friction you feel when it finally tightens that holds it together.  If the thread in the prop is about to strip, you'll feel it stretch & strip as you tighten it.  It simply won't tighten.

If it were holding some kind of flange or joint that's subject to a lot of force then things might be different, but relative to the size of the thread, there isn't much force attempting to strip the threads.
That said, if it bothers you, change it.

Thanks for reassuring suggestions I think I'll leave it for now.

I agree with your concerns about the bulge in the motor thread eventually wearing/stretching out the threads in the prop. Being that the bulge is in the first thread it will wear on every thread in the prop as it is spun on. I wouldn't hesitate to carefully file it down until the prop spins on freely. Filing the first one will not have any adverse effects. Put some tape on the motor opening to keep filings out of the motor windings. Other options, tighten it down and leave it on, or replace it..... Good luck.