I'm trying to dismantle some wall boards, but I don't know how to remove the pictured bolt - close up attached. Its head has the dome shape of a carriage bolt, but there is a hole in the center, with a square-shaped pin deeper inside. Note the hole is circular and not hex, so this is not an allen bolt. Its a wood-and-fiberglass board attached to a metal frame. I would love to cut up the board, but the metal frame surrounds the entire board, and is attached with these bizarre bolts. Any suggestions or ideas would be most appreciated. Thanks!
This is a pop rivet, not a bolt. It can only be removed destructively.
Drill out the center with a drill bit meant for metal (as opposed to a brad point bit, for instance) until the flange come off. Use a bit roughly half the diameter of the flange.
When the flange breaks free, it will get stuck on the tip of your drill bit, which you will then remove with pliers.
2... those who know history are doomed to repeat it... Nov 25, 2016 at 15:52
2Roughly speaking, you want the diameter of the drill bit to be about 1/2 the diameter of the flange. Nov 25, 2016 at 16:03
4I do think changing "Pop rivet." to "
This is a [pop rivet](https://en.wikipedia.org/wiki/Pop_rivet), not a bolt. It can only be removed destructively." would improve the answer significantly - OP clearly hasn't encountered them before.– zwolNov 25, 2016 at 19:12
8@User95050 My edits didn't contradict your answer in any way, and clearly improved it; you'd even have gotten any resulting additional up-votes. Being proprietary isn't how we work here, as the goal is not to own the best answer; the goal is to collectively result in the best answer. Nov 25, 2016 at 21:52
5The edited version from Daniel is a better, more informative answer.– MarkNov 25, 2016 at 23:48