Excellent question. Inside the bracket to the inside edge of the disc is only 1/2". Obviously in your case that will not clear. The disc itself is almost 1-7/8" in diameter as well.

You essentially need a desk edge that has NO lip - as was the case for me with the desk I put mine on. I have two of them for my two monitors.

You could put the mounting bracket "backwards" and use the holes to screw it in to the desk, rather than being clamped. I did not need to do this, but that obviously would not be as secure, depending on how well the screws bit in to the desk.

These are GREAT mounts, highly adjustable. Maybe a new desk?? :)