I'm designing something in which an insert fits into a piece of steel square tubing. The insert is held in place by a set screw threaded in the insert, which is in turn loc-tited into an aluminum "plug" (wider surface area) and is clamped to the inner wall of the square tubing with a hex wrench via a hole in the square tubing which allows access to the hex head. One thing I don't like is that the integral nature of the set screw/plug tends to want to move the tubing/insert out of alignment. As you tighten, the plug is pushing to the right on the tubing and wants to push the whole insert to the left. This made me think of c-clamps and that "swivel head" on the end. See an example here. Is anyone aware of a screw attachment like this? Essentially a swivel-end for a screw? This would keep my force normal and prevent this undesirable lateral force on the tubing/insert.