Why are these 3 letters on almost all of my zippers?
The video explores the engineering genius behind zippers, from Whitcomb Judson's failed hook-and-eye design to Gideon Sundback's revolutionary 1914 patent that remains virtually unchanged today. It explains how YKK became the dominant zipper manufacturer despite Talon's original patent rights, and reveals the mechanical principles that make zippers work through Y-shaped sliders and precisely shaped teeth.
Summary
This video examines the surprising engineering complexity and history of zippers, beginning with Whitcomb Judson's problematic hook-and-eye fastener design from the 1890s. Despite being a poor inventor but excellent salesman, Judson founded the Universal Fastener Company after showcasing his device at the 1893 Chicago World's Fair. His design was deeply flawed - it jammed constantly, had to be removed before washing, and would pop open entirely if a single hook came loose. The breakthrough came when Swedish engineer Gideon Sundback joined the company in 1906, initially to court the manager's daughter whom he later married. After his wife's death, Sundback channeled his grief into work and developed the modern zipper design in 1914. His innovation involved Y-shaped teeth that are wider at the end than their corresponding openings, making them difficult to force together directly but easy to connect through a Y-shaped slider cavity that tilts teeth at the correct angle. Sundback also created revolutionary manufacturing machinery that could produce 150 meters of zippers daily with unprecedented precision. The product initially found niche applications in money belts and rubber boots, with B.F. Goodrich coining the term 'zipper' for the sound it made. Despite being more expensive and temperamental than buttons, zippers became popular because they represented modernity and convenience. The video explains three main zipper types: metal, plastic, and coil zippers (the most common), with coil zippers being a single molded piece that prevents individual tooth failure. Modern zippers include locking mechanisms with metal pins that prevent accidental opening. The narrative concludes with YKK's rise to dominance after Sundback's patent expired in 1934, when Japanese businessman Tadao Yoshida founded YKK and focused on quality and vertical integration, eventually producing 10 billion zippers annually and surpassing original patent holder Talon.
About this episode
How do zippers work? Sponsored by Hostinger. Host OpenClaw on a Hostinger VPS plan: https://www.hostinger.com/veritasiumopenclaw - and use code 'veritasium' for an extra discount. If you’re looking for a molecular modelling kit, try Snatoms, a kit I invented where the atoms snap together magnetically - https://ve42.co/SnatomsV Sign up for the Veritasium newsletter for weekly science updates - https://ve42.co/Newsletter ▀▀▀ A huge thank you to Prof. Robert Friedel for his invaluable expertise and contributions to this video. Check out Friedel’s book here - http://ve42.co/friedel-zipper Massive thanks to IPFL for fabricating our giant zipper - https://ve42.co/ipfl-fabrication A huge thank you to Emily Zhang for her advice on how to best structure this story. Check out her new channel here: @rabbithole_video The giant zipper was adapted from an original design by LoboCNC - https://ve42.co/fidget-zipper We’d also like to thank everyone at YKK who helped organise our call, especially Sophia Seco, Engin Ertugrul, Christelle Malot and Matthew Rawstron. Finally, a big thank you to Christopher Anderson, Anna Oros and Pressley Stevens of the Allegheny College Library for sending us footage of Whitcomb Judson’s original fastener in action. ▀▀▀ 0:00 The First Zipper 2:51 Who invented the zipper? 4:20 How does a zipper work? 5:51 The Zipper Maker Machine 7:46 Why is it called a zipper? 9:32 The Novelty Of A Zipper 12:57 The Most Popular Zipper Doesn’t Have Teeth 14:08 Zippers Have A Lock 15:31 Why do zippers have YKK on them? 18:39 How To Fix A Zipper ▀▀▀ References and Visuals can be found here - http://ve42.co/ZippersRefs ▀▀▀ Special thanks to our Patreon supporters: Adam Foreman, Albert Wenger, Alex Porter, Alexander Tamas, André Powell, Anton Ragin, armedtoe, Balkrishna Heroor, Bertrand Serlet, Blake Byers, Bruce, Charles Ian Norman Venn, Daniel Martins, Data Don, Dave Kircher, David Johnston, David Tseng, EJ Alexandra, Evgeny Skvortsov, Garrett Mueller, Gnare, Hayden Christensen, Hong Thai Le, Ibby Hadeed, Jeromy Johnson, Jesse Brandsoy, Jon Jamison, Juan Benet, Kelcey Steele, KeyWestr, Kyi, Lee Redden, Marinus Kuivenhoven, Mark Heising, Martin Paull, Meekay, meg noah, Michael Krugman, Moebiusol - Cristian, Orlando Bassotto, Parsee Health, Paul Peijzel, Richard Sundvall, Robson, Sam Lutfi, Shalva Bukia, Sinan Taifour, Tj Steyn, Ubiquity Ventures, Vahe Andonians, wolfee ▀▀▀ Writers: Daniel Leonard & Gregor Čavlović Producer & Director: Daniel Leonard Presenter: Gregor Čavlović Editor: Trenton Oliver Animators: Domonkos Józsa, Fabio Albertelli & Andrew Neet Illustrators: Jakub Misiek & Emma Wright Additional Editor: James Stuart Researchers: Callum Cuttle & Sophia Rose Camera Operators: Gregor Čavlović & Henry van Dyck Thumbnail Designers: Abdallah Rabah, Ren Hurley & Ben Powell Production Team: Josh Pitt, Matthew Cavanagh, Anna Milkovic, Katy Southwood, Glen Griffiths & Jess Bishop-Laggett Executive Producers: Derek Muller, Gregor Čavlović & Casper Mebius Additional video/photos supplied by Getty Images & Storyblocks Music from Epidemic Sound
Key Insights
- Judson's original hook-and-eye fastener was so flawed it had to be completely removed and unsewn from garments before washing, and a single misaligned piece could cause the entire fastener to pop open
- Sundback's grief over his wife's death led him to throw himself into his work, resulting in the major breakthrough of the modern zipper design that abandoned the hook-and-eye approach entirely
- The Y-shaped slider cavity works by tilting teeth at precisely the right angle so they can slot into grooves without bumping into the tooth above, while a wedge separates them during unzipping
- Sundback had to invent extraordinary manufacturing machinery because no existing tools in the 1910s could reliably shape the tiny teeth with the precision required for his zipper design to function
- YKK surpassed original patent holder Talon by focusing on quality above everything else and manufacturing everything in-house, eventually reaching 10 billion annual zipper sales while Talon's US market share fell to just 7%
Topics
Transcript
[0:00] (zipper whirring) - How does a zipper actually work? Like try to push down on a zipper from above and it probably won't budge, but if you just use the pull tab, suddenly it's buttery smooth. So how does it do this? We've made more zippers than there are stars in the Milky Way. You probably used one 10 times today without even noticing, except the only time you do is when one breaks. I'll show you what to do when this happens, but what is actually going on inside this thing? I mean, obviously the teeth come together inside the slider, [0:30] but it turns out there is a surprising amount of engineering to this thing. All of…
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