This is a part of the inner life of a lock cylinder. Springs and a piston. Note that those parts have only 2.5 milimeters in diameter. I took those out of a lock I had to break on my workplace. I will post the broken core of the lock tomorrow to give an idea where those parts belong to.

This piture gives a good view of the tight range field deepth of the Sigma 105 Makro Lens.