Here's a picture of an acropora frag from Tonga. I won this at a raffle during our club meeting, I think it was in October. This frag was glued in Tonga to the head of a nylon screw using IC Gel crazy glue. I "epoxied" the screw onto the side of a small live rock. Note how the frag has totally encrusted the head of the screw. You can still see the outline of the thread that has also been encrusted by coralline algae.