Five-Sided Bolt and Nut

A model inspired by the unique bolt from The Martian by Andy Weir."But then [Watney] was distracted by a bolt in one of the bulkheads. It only had five sides. He wondered why NASA decided that bolt needed five sides instead of six. It would require a special wrench to tighten or loosen. …he wondered where he could get a cool five-sided bolt like that."- The Martian (Andy Weir), chapter 26Well, Watney and you can now have your very own five-sided bolt. I added a matching nut which makes for (in my experience) a very entertaining fidget as well.