Impossible screw

<span class="testo">The magician holds a double headed bolt, having the two threaded pivots of different dimension: one is bigger and the other is smaller. Now he threads one nut on the small pivot and then on the bigger one&hellip; the IMPOSSIBLE thing is that he always uses the same nut! In the end he hands the two pieces to a spectator asking him to do the same&hellip; obviously he won&rsquo;t manage to!<br />
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&bull; No skill required, it can be repeated immediately.<br />
&bull; The item is made of brass, everything can be examined.<br />
&bull; When the nut is screwed on one of the two pivots, the bolt is cm 4,5 long (in. 2) and its diameter is 1 cm.</span><br />