Robert Swinney wrote:

Once I made a "hex" head bolt and nut from 2 inch brass and left it on my
desk at work as a paper weight. The bolt head was not really hex but had
seven faces rather than 6 and the thread was left-handed. Visitors would
invariably pick it up and play with it while talking or waiting for me to
get off the phone. Everyone would notice the left-hand thread, but almost
no one picked up on the seven-sided head until I asked, "Do you see anything
else strange?"

Bob Swinney

Just the bolt or both? Sound like a neet thing to do. I'll have to try it.
...lew...