The magician shows a holed nut and bolt. A spectator is asked to screw them together until the holes are perfectly lined up. The performer makes the chain passing through the holes. The spectator is able to confirm that the nut and the bolt are locked by the chain.
The chain is then removed and the nut unscrewed from the bolt. The performer borrows a ring from a spectator and the bolt is put through the ring. Then the nut os crewed and locked by passing the chain through the hole. The spectator holds each end of the chain. The performer covers the bolt and the nut with a handkerchief.
While the spectator is till holding the chain, the magician removes the ring from the bolt. All props can be examined after the performance.
All can be examined
Easy to perform
Very visual effect
The trick is delivered with an internet code for you to watch bonus video clip including performances and explanations.