Having trouble locating what I need. I tried hd online chat and the guy was clueless. It's difficult to even search for this. I need a cable clamp for my inlet box with a 1/2 inch knockout. The 3/8 hole was too small. I thought of just dremeling it to be a little bigger, but don't know if that could cause a problem later on with a sharp edge touching the sheathing. Thanks for any help.