What it takes to make a zipper

Picture it. You're late for the airport. You stuff one more sweater into the suitcase, lean on the lid, and pull the zipper all the way around in one long rip. It doesn't snag. It never does.

You've never once looked at the little tab. If you did, odds are it would say three letters: YKK.

So how did one company end up on so many of them?

In today's Low Tide: what it takes to make a zipper, and the make-or-buy line: why the part you can buy, your rivals can buy too.

What it takes

The obvious answer is a better zipper. Better teeth, a smoother slider, a clever patent.

Look at what happened to the company that had all of that first.

In the 1960s, the American maker Talon was on seven out of ten zipper tabs in the US. A decade later it had lost half its market share. Today it barely registers. It stopped getting more productive, so its prices stayed too high, and it stayed home while clothing factories moved abroad.

YKK did the opposite. It went abroad early, with factories near its customers. And it did one thing nobody else did: it built the machine that makes the zipper.

In 1950 YKK bought an American chain machine. By 1953 it had improved on it: its founder, Tadao Yoshida, designed a mechanism that feeds the teeth into the machine one at a time. It became YKK's patent No. 1. By 1964 YKK was building its own chain machine, the CM6, which punches the teeth out of flat wire. It's now on the Japan Society of Mechanical Engineers' list of engineering heritage.

Then it kept going. YKK brought every step in-house, down to smelting the brass and dyeing the cloth. Today it runs a whole Machinery and Engineering Group that develops and builds its equipment.

Here's why that decides it. Unlike its competitors, YKK built its growth on its own equipment and materials. When the same suppliers serve every maker, everyone shares the same machines, and there is nothing left to be better at except price. YKK made the one thing nobody could buy.

That's how it came to hold about 40% of the world's zipper sales by value but only 20% by volume (as reported in 2017): its zippers sell for about twice the average price (our arithmetic).

Back at your desk

In 1937 the economist Ronald Coase asked a strange question: if markets are so efficient, why do companies make anything themselves? His answer: getting something through the market costs more than its price. Firms make things in-house when that hidden cost is too high.

Here's the part Coase didn't say, and YKK shows: whatever you buy, your competitors can buy too. That's one lens on YKK, not the whole story; going abroad early mattered too.

One question for your next planning meeting:

What are we buying that everyone else buys?

The same AI model. The same design system. The same analytics stack, the same onboarding template, the same agency. None of that is wrong. But none of it can be the reason anyone picks you.

Find yours

So where's the machine in your product?

Name what everyone buys. List the five parts of your product your competitors could get from the same vendors tomorrow. That's your commodity layer. Fine to buy.

Strip what you inherited. For each part you build yourself, ask why. Some of it is a habit from a team that no longer exists. Building the wrong thing in-house is as expensive as buying the right one.

Find the one machine. Which single step, if you owned it, would make you faster or better in a way a customer can feel? That's the part worth building. Even YKK bought its plastic pellets.

At low tide

A zipper is mostly the machine that made it.

What's the machine behind yours?

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Every claim is sourced below; corrections are published. Sources: The Conversation, Hot competition for the humble zipper; Japan Society of Mechanical Engineers, Mechanical Engineering Heritage No. 49, Zipper chain machine YKK-CM6; FashionNetwork, YKK invests to compete in entry-level segment (2017); Wikipedia, YKK and The Nature of the Firm.