Crack One Open

How the modern-day aluminum beverage can was made safer and more eco-friendly by one man’s invention—a riveted tab that opened the can, but stayed attached.

By Ernie Smith

Today in Tedium: When it comes to soft drinks, safety is a big deal. After all, these drinks are widespread enough that when they are not managed properly, they can create society-wide problems. (There was a small freak-out about aspartame, the sweetening agent of Diet Coke, being possibly carcinogenic, but the concern may be a bit overblown.) Earlier this year, we highlighted one such society-wide problem—the story of how Canada had a broken-bottle mess on its hands in the late 1970s because the design of large glass soda bottles made them shatter everywhere. It turns out that glass bottles weren’t alone—aluminum cans also had a major safety problem, and it had everything to do with how they were opened. Today’s Tedium discusses the guy who made aluminum soda cans safe. — Ernie @ Tedium

Today’s GIF is from a guy who claims to be an expert at generating a satisfying aluminum-can-opening sound.

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Early canned beverages required tools to open—which you don’t remember because you weren’t born back then

When the news of the first aluminum beer can first emerged out of Richmond, Virginia, in 1935, it was such a big deal that the beer company that announced it needed to pre-announce the news in the local paper.

The beer at the center of this invention, just before the announcement, changed its name. No longer would it be called Boar’s Head Cream Ale—it was now Krueger’s Cream Ale. But the eye-opening detail of the ad was this:

Watch for startling news in this paper January 24!

Richmond will be the first city in the country to learn of the most revolutionary event in the history of American brewing. Watch for it!

Revolutionary was right. The “keglined can,” as it came to be known, became a key element of how we consumed beverages. The can solved a problem that had previously made beer a no-go in canned form: The can could change the flavor of the beer.

The secret of this can was not the physical design; it was the lining. As John H Murch’s patent filing, originally assigned to the American Can Company, explains, nailing the coating was a challenging problem when it came to beer:

Where the sheet is first coated and then formed into the can parts some of the lining material is often dislodged and the surface is scratched in the can making operations, and where such breaks in the coating occur the can is unfit for commercial use. Cans have also been coated with a lining material after the end has been secured to the can, but in this case it has often been found that the coating fails to properly flow into the bottom connecting parts of the can end and body, being held back in part by capillary or surface tension of the coating and where even a slight metal is left exposed it reacts upon the beer and makes the can unfit for use.

The solution they came up with relied on adding a flange to the bottom of the can, then spraying it with a coating material, then applying the lid.

Just one problem, of course—how do you open the thing? The American Can Company’s recommended solution was to use a church key. The first ad promoting the Keglined can recommended: “Be sure to ask your dealer for a ‘Quick & Easy’ opener and learn the simple little trick of opening your can of ale or beer.”

Despite the seeming added complexity of having to use a can opener to open a can of beer, the new method was quite popular among beer-makers and consumers alike. As Breweriana reported, the method gained early nods from readers of Brewer’s News, who saw it as a way to ensure the beer tasted like a draft—and Krueger’s scored a market win, as by August 1935, the company was buying 180,000 cans per day—and national competitors, like Pabst and Schlitz, responded by producing cans of their own.

Cone Top Beer Can

A 1946 Neuweiler beer can, utilizing a “cone top” design that served as a bridge to the cans we use today. (Wikimedia Commons)

Some of these makers, particularly Schlitz, used “cone top” beer can designs—a design approach actually popularized in the United Kingdom by Felinfoel Brewery, which allowed the cans to use traditional bottle tops. Both types of can designs were common for a while, but ultimately, the flat top’s more efficient design won out.

Of course, neither design was used during much of the 1940s, when wartime demands for metal put the beer can on ice for a while—and when they returned, it was without the tin that defined the earlier can designs. Too bad, too—because someone had just figured out a way to open them without a can opener.


The year that the first aluminum beer can emerged. The beer, called Primo, was seen as a big deal—enough so that its maker, the Hawaii Brewing Company, took out an entire section in the Honolulu Advertiser to promote the “shiny-steinys.” Unfortunately, the brew proved to be a bit of a disaster for all involved, in part because of the can was poorly sealed, leading the beer to go bad in some early shipments. Also not helping: The thinner metal was such that when you used a church key to open it, there was a real risk it would open the side as well as the lid—and also a real risk that when you opened, the can would splatter you with beer. Per, the company ended up going belly-up in 1963. However, another well-known beer company, Coors, had developed the can design and perfected it themselves.

Shasta Diet Cola

These pull-tab can designs were common in the 1960s and 1970s—but they came with some notable risks. (Roadsidepictures/Flickr)

The problem with pull-tab can lids: They were dangerous

As you are likely getting from this piece, it took a while to get the more modern designs that we’re used to from our beer and soda cans. One of the most important elements of this whole endeavor is the pull-tab lid, which did not actually become popular until the 1960s and 1970s.

While the earliest designs for pull-tab sodas came about in the 1960s, the general idea had actually been in the works starting in the 1930s, just before World War II. It took a while for the cans to get back there, with the rise of the aluminum can playing an important role in its uptake.

A key figure in this whole endeavor is Ermal Fraze, who came up with the idea for the removable pull-tab after … you guessed it, he forgot his church key before a picnic. That day, Fraze—an engineer who founded the Dayton Reliable Tool Company, improvised by using a car bumper as a makeshift church key, but it gradually led him to develop a pre-puncture pull-tab, which he patented in 1964 and quickly sold to the Aluminum Company of America (ALCOA).

The early forms of these tabs were actually designed to be removed from the can entirely, and (as highlighted in the British Coca-Cola commercial above) were sold as a tool of convenience—after all, if you didn’t need to worry about the pull tab, you no longer needed to carry a church key around.

There was just one problem—because the tabs could be removed entirely, they created serious side effects. People would throw them on the ground thoughtlessly, creating issues of littering or even risk of injury—after all, we’re talking about sharp pieces of metal pulled from beer or soda cans.

But even more dangerous was the risk of people accidentally swallowing the tabs. It was a serious enough problem that in 1975, the Journal of the American Medical Association actually included a piece discussing how they could be accidentally ingested, creating serious risks of medical disorder.

It turns out that one problem might have led to another. As noted in a Tampa Bay Times piece in 1975, an eco-friendly suggestion—dropping the tab in the can once you’ve pulled it off—was leading to real-world emergency room issues. (Not helping, either, was that pull-tabs were hard to detect via X-rays.)

So, to put it simply, the pull tab was a lot more dangerous than it looked at the outset.

Fortunately, an inventor was working on it.

“Coors doesn't taste great to begin with, and it tastes even worse when mixed with blood.”

— Rain Noe, a senior editor for the design site Core77, discussing why a competing design for the pop-top can, the push-tab design developed by Coors in the 1970s, failed to break through. The design relied on users to push in two spots on top of the can, which meant that there was always a risk that as you pressed in, you would cut yourself on a sharp piece of aluminum. While solving the problem of pull-off tabs—and seeing use by brands such as R.C. Cola—it just wasn’t good enough to stick around.

Soda Can

A shockingly innovative design. (Wojciech Kulicki/Flickr)

The riveted tab that quietly changed the world

In many ways, Daniel F. Cudzik was one of those people who might have faded into the ether. A longtime employee of the Reynolds Metals Can Division, he is credited for a number of inventions related to the opening of cans—including the stay-put tab design and perforated can wall that we use today to open up cans.

And like the creation of the original beer can itself, it has ties to the Richmond area, where the Reynolds Metals Company was based.

Cudzik did not come up with this idea out of thin air. The person who can be credited for the original idea is Richard Steele, an early market researcher who was helping the Reynolds with their cans. With reports emerging of medical issues involving the pop-tops, he suggested to the company’s leadership that a tab that stayed on the lid might be a good idea.

It took him a few tries to find the right approach. His first attempt, called the “Non-Detachable Easy-Open End Closure,” basically used a mechanism that allowed the can to open up a spout on its side—which worked, but made it basically impossible to drink the beverage out of the can itself.

Sta Tab

The design that changed soda forever.

But he kept trying, then landing on a U-shaped design for an “Easy-open wall,” with an opener tab held on by two small rivets. But eventually, he hit pay dirt with a second “Easy-open wall” patent filing. with the trademark one-rivet design that you’ve probably used to open a White Claw sometime in the past 24 hours. As Cudzik’s patent filing put it, this was the one:

The container industry is highly competitive and has long made serious efforts to design easy-open can ends, particularly of the kind used to contain beer and carbonated beverages, so that the tear strips and tabs could be secured non-detachably while still remaining convenient to operate and use, and free of substantial cost penalties. These efforts have produced many designs, but none before the present invention appears to have provided a solution of the problem unaccompanied by one or more difficulties which make the design as a whole commercially unsatisfactory.

Key to the effectiveness of the product is the tab design, the patent notes: “The opening construction of the invention requires a tab which must be stiff against transverse bending and yet flexible and tough enough at the connection between the tab and end wall to permit lifting and retracting the tab without causing a fatigue crack at the connection.”

The thickened, folded-over piece of aluminum created just enough force to break through a slightly perforated plate of aluminum without creating a piece that could be pulled off. Sure, people have done it, but it’s a lot harder to do and that means the design is much more of a deterrent.

He even thought about things that you perhaps don’t, such as the direction the spray vents when a can is opened:

The spray which normally accompanies such venting will then be directed against the under-surface of the tab which thus acts as a shield to protect the user from the spray, even if undesirably high pressures had developed inside the container, as by agitation.

That’s the kind of thing you discover when you put in the work to improve this engineering.

His design, by just a few years, beat out Ermal Fraze’s attempt at the same idea, the “Easy Open ecology end,” which took a very similar approach.

These inventions each had some hugely significant side effects. As ‌Materials, a 1999 report by the U.S. Interagency Working Group on Industrial Ecology, Material and Energy Flows noted, the design allowed hundreds of thousands of metric tons of aluminum to go back into the recycling stream, rather than on roadsides and city streets the world over. All those little tabs add up.

Alas, despite all that work, people still swallow tabs from time to time, despite rivets that should make the job way harder.

Still, though, this was one invention that had a lasting positive impact on our world.

Beverage can designs have come a long way from the days in which we needed to solder together pieces of tin foil into a single, consistent piece.

These days, in fact, the entire can is just three pieces—one highly molded cylindrical body, which goes through a complex process that really highlights how moldable modern soda cans really are; a lid, placed on at the end of the process; and the pull tab.

A hugely popular video from 2015, starring “engineerguy” Bill Hammack, explains how they are able to build these can designs to maximize weight, size, and functionality. Aluminum’s malleability is a key element of the whole thing. Also key: The dome design at the bottom, which adds rigidity and offers a small, subtle nod to its roots as a good of manufacturing, thanks to some imprinted characters on the bottom.

Worth watching in tandem with Hammack’s video, to get an idea of how the principles play out in action, is this video showing how aluminum cans evolve in the factory from giant sheets of aluminum with the thickness of construction paper.

Recently, a guy went super-viral on TikTok by pointing out that the dome at the bottom, which Hammack says is used to reduce the amount of material needed in the can, can be used to open the can. (My wife told me about it.)

While I can’t find evidence that this was the goal of the invention, it would not surprise me. The beverage industry has been improving this basic design for 90 years, and they have made literally tens of billions of them.

It’s easy to take these devices for granted because they’re so overwhelmingly common, but we make so many and have been doing it for so long that they have become some of the simplest, yet most advanced, pieces of engineering that the world has known.

Plus, we were able to get rid of our church keys.


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Ernie Smith

Your time was just wasted by Ernie Smith

Ernie Smith is the editor of Tedium, and an active internet snarker. Between his many internet side projects, he finds time to hang out with his wife Cat, who's funnier than he is.

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