How tight should you screw the kitchen faucet into the sink?

[peterwesterlund]

As mentioned, how tightly should one fasten the kitchen faucet to my metal sink? You don't want it to be the slightest bit loose and "wobble." But if I screw it tighter, there will be a small "moat" around the faucet because the metal gets pressed down.

What should one do?

 

[sblixten]

I think like this:
It should not be able to move in relation to the metal sheet, but it doesn't matter if it moves a little together with the metal sheet.

 

[cpalm]

Sounds like the spacer block on the underside between the sink and the nut is the wrong dimension (hole too big)?