I have a under mount sink in granite counter top. The 1/8 inch thick edge of the sink (at top where it sticks with the counter top) does not let faucet mounting bracket to rest flat with the counter top. I am unable to tight the nut and the faucet is little loose. Any body have any idea what need to be done?

I guess try a fat rubber washer to absorb the difference in the surfaces.

That's a good idea! Thanks you very much.

Good idea from Joypulv. You will have to live with this since the person who cut the hole made it too close to the sink edge. You could also try using plastic shims found at a good hardware store, maybe even HD or Lowe's, look in their hardware boxes. They may allow you to tighten the faucet a bit more than rubber.

Some 1/8 Plexiglas with properly located holes or notches might also work.