Is the gap normal? And how many mm is this watch?

JwRosenthal

Looks like a nice watch and congratulations on your first nice watch! As has been said, it’s a screw down crown so either it isn’t fully engaged in the pics, or is cross threaded. As Don said, the best way to avoid cross threading is the turn is backwards slowly as you push in and you will feel it click into place on the threads, then turn to screw it down. It’s all about finesse and never brute force.

Omegafanman

This might help in terms ...and turns... of how the screw in crown should operate assuming it is correctly fitted and not cross threaded....