Having read about the issues many have had regarding the stiffness of the SM300 service case crown I was quite gratified that I did not seem to have this problem. After setting the time I would always turn the crown anticlockwise against the thread to get the gentle click that indicates the threads are aligned before carefully screwing the crown closed.

Lately though I'm finding the threads rather hard to line up, very vague and difficult to locate the "click" without a lot of fiddling. Once engaged the crown only appears to rotate one and one third turns until fully closed. At the risk of sounding a bit paranoid I'd like to find out from other owners with this case how many turns is normal as I honestly never really registered until experiencing this vagueness. The crown definitely closes fully so there is no blockage I'm a bit worried about crossed threads or some such.

 

If you imagine what you are actually doing with the threads when you do the little backwards turn trick to hear/feel the click, it's not surprising that it's getting more difficult to find. If you are getting about 1.5 turns of the crown to thread it down, I would say that's pretty typical.

Cheers, Al

 

Al, would it be better to simply screw it in without attempting to line up the threads? I understand that by lining them up like that I may be causing the start of the thread to become deformed, and though I am normally quite careful this crown is actually a bit difficult to get a grip on and I probably end up inadvertently using too much pressure.
I always just did it like that through fear of cross threading without realising that I might actually be causing damage.

As always thank you for your input.

 

If you don't have a crown seal that is really tight on the case tube, then it should be pretty easy to start the threads without doing the backwards turn. Just go slow and don't use a lot of pressure towards the case. I wind these watches all the time and yes they can be a pain, even if the crown isn't super tight...for my own SM300 I keep it on a winder to minimize the amount of crown interaction I need to have with it.

Cheers, Al

 

Thanks Al, yes I just did that now and it was fine. Funny how a preconceived idea can make me do something unnecessary and potentially harmful. The crown is not overly tight just a bit fiddly to grasp with its rounded end.