Keeping Faucets From Spinning on Granite

I am putting a granite countertop on a bathroom vanity and installing new faucets. This vanity number two. When I attached the faucets to the first vanity there was a warning in the instructions not to tighten the bolt that holds the faucet too much because you can crack the granite. I tightened them as much as I dared, but both faucets have rotated about 5-10 degrees past where they should be because they apparently move a tiny bit every time you turn the faucet off.

How do I prevent this? I'm about to install a second countertop and new faucets. Do the screws just need to be tighter? If it just needs to be tighter, how do you what is tight enough and when you are in danger of cracking the granite? Would some type of rubber gasket help?

Thanks for any advice.

Many faucets come with a gasket that fits underneath. That usually will keep the faucet from moving if it is tight enough.

Is the slab 2 or 3cm? That will make a difference in how tight you can do things.

Your plumber may hate you, but you could silicon it in place...it won't move once that cures. A razor blade will allow you to scrape off any that gets outside (do it right after you install, and just have the blade vertical - be careful not to scratch the faucet- you could put a piece of tape around it first). If done right, you'll not see any caulk, and it will be a major bear to get the faucet out for repair or replacement!