Pop cans are made of aluminum, but not a single uniform sheet of it. A standard beverage can uses two different aluminum alloys, a thin polymer lining on the inside, and printed coatings on the outside. Each layer serves a specific purpose, from holding carbonation pressure to keeping the acidic drink from eating through the metal.
Two Alloys, Not One
The body and lid of a pop can are made from different aluminum alloys because they need to do different jobs. The body is alloy 3004 (or the nearly identical 3104), which contains about 97.8% aluminum, 1.2% manganese, and 1.0% magnesium. This blend is soft and flexible enough to be stretched into the tall, thin-walled shape of a can without cracking.
The lid uses alloy 5182, which is significantly harder. It contains about 95.2% aluminum, 4.5% magnesium, and 0.35% manganese. That extra magnesium makes the lid rigid enough to withstand the internal pressure of carbonation without bulging, and strong enough to hold the scored opening and the pull tab. The tab itself is also stamped from a separate strip of aluminum and riveted into the lid during manufacturing.
How a Flat Disc Becomes a Can
Pop cans are made through a process called drawing and ironing. A punch press stamps out a flat aluminum disc about 14 centimeters in diameter, then bends it into a shallow cup in the same step. That cup moves to another machine where a tool draws the aluminum upward, stretching and thinning the walls to form the tall body of the can. By the end, the walls are paper-thin, far thinner than the base.
After the body is formed, a machine called a necker gradually narrows the top of the can to create the smaller opening where the lid will attach. This narrowing happens in about 11 incremental steps. Doing it gradually prevents the thin aluminum from tearing. The lid is manufactured separately on a different press, then seamed onto the filled can at the bottling plant.
The Invisible Lining Inside
If you could peel back the inside of a pop can, you’d find a thin polymer coating between the aluminum and the liquid. This lining exists because sodas, energy drinks, and sparkling water are acidic enough to corrode bare aluminum. Aluminum naturally forms a thin oxide layer that protects it from corrosion, but acidic beverages dissolve that layer. Without the polymer barrier, the drink would slowly eat into the metal, picking up a metallic taste and eventually weakening the can.
For decades, the standard lining was an epoxy resin based on a compound called BPA (bisphenol A). These coatings offered excellent chemical resistance and durability. However, concerns about BPA’s potential effects as an endocrine disruptor have pushed the industry toward alternatives. In December 2024, the European Commission adopted an outright ban on BPA in food contact materials. Many manufacturers now use polyester, acrylic, or vinyl-based coatings instead, though the transition is still underway in different markets. Beverage cans specifically tend to use epoxy-acrylic resins as a common BPA-free option.
What’s on the Outside
The colorful branding you see on a pop can sits on top of another set of coatings. After the can body is formed, it’s coated with a base layer, printed with colored inks, and then sealed with a clear protective varnish. This outer varnish prevents the inks from scratching off during shipping and handling. The exterior coatings also protect the outside of the aluminum from minor environmental corrosion, like moisture from condensation or refrigeration.
Recycled Content in Every Can
A pop can you buy today isn’t made entirely from freshly mined aluminum. The average aluminum can produced in the United States contains about 71% recycled content, according to the Aluminum Association. That figure is down slightly from 73% a few years earlier, but it still dwarfs the recycled content in competing packaging: glass bottles average around 23%, and plastic bottles range from just 3 to 10%.
Aluminum’s recyclability is one of its defining advantages. Unlike plastic, which degrades in quality each time it’s recycled, aluminum can be melted down and reformed into a new can with no loss in performance. A recycled can requires about 95% less energy to produce than one made from raw ore. The entire cycle, from recycling bin back to store shelf, can happen in as little as 60 days.
Why Aluminum Replaced Steel
Pop cans weren’t always aluminum. The first all-aluminum beer can appeared in 1959, and aluminum beverage cans entered wider production by 1965. Before that, cans were made from tin-plated steel, which was heavier and more prone to corrosion. By 1985, aluminum cans dominated the beverage market. The lighter weight reduced shipping costs, the material was easier to chill, and the growing recycling infrastructure gave aluminum a sustainability edge that steel couldn’t match. Today, virtually every pop can sold in North America is aluminum.