I know that one, an old machinist taught it to me. People are just amazed when I show them!
Richard McKenna, of The Sand Pebbles fame, had a collection of short stories, The Left-Handed Monkey Wrench. The eponymous story had a main plot but a side-story was a chief machinists mate asking a seaman for one. The victim fell for it and everyone had a good yuck at his expense. Thereafter, whenever he appeared in the background he was always fiddling with a bit of metal. At the end of the story, the chief needed to tighten some pipe and asked for a monkey wrench. The kid slapped one in his hand, he thumbed the adjuster, and the wrench slipped off of the pipe barking his knuckles. The seaman had made a wrench with a left-handed thread on the adjuster.