I recently completed a granite tile countertop project and I now have a problem trying to install a new drop in kitchen sink into the countertop.

The total thickness of the countertop build up is almost 2" ( 2 layers of 5/8" plywood with adhesive between the sheets / thinset / ditra underlayment / thinset / 3/8" granite tile). The bolts that are supplied with the sink are not long enough for the supplied clamps to secure to the underside of the plywood.

Does anyone know where I can find longer bolts or extension for the supplied bolts? I am also open to any other solutions to this problem.