PRIMADAExtra-Strong Set magnetic hooks, 2pc, Chrome

Will they work on aluminum?

Do they rust if they get wet?

Are the magnets securely attached? The last ones I had, the magnet part and the hook part came apart easily, and I'm concerned about child safety.

what is diameter of the hook itself? I want to hang a calendar. Calendar holes are usually about 1/8". The hook I have been using is 1/16" .