Imagine losing one nut and not being able to buy another, because nobody else's fits. 🔩

That was the world 200 years ago. Every workshop cut its own thread, angle and spacing. Then Henry Maudslay and Joseph Whitworth pushed for one standard, a fixed number of threads for every size. It didn't happen overnight, but in time a bolt from one workshop fitted a nut from any other.

Most of the world now uses the 60 degree metric thread, but the idea is still his: agree once, so everything fits.

Did you know nuts used to belong to their bolt like a key to its lock? Send this to someone who has fought a nut that wouldn't fit.

Next time: how a bolt is actually made.