People may take can openers for granted, but these nifty tools have an interesting history. They have evolved into many forms over time. But the strangest detail is that they weren’t invented until decades after the invention of canned food. One of the early iterations was the can opener key. It was much smaller than the modern version, but it also took a lot of patience to use. If you frequent thrift stores and antique shops, you’ll know what this mysterious key can open.

The History of the Can Opener Key

The story, of course, begins with the invention of cans. In 1795, Napoleon Bonaparte offered a reward for anyone who could invent a way to keep food preserved so his army’s supply could stay fresh while they were delivered to his troops. Scientist Nicolas Appert won for his invention using glass jars and lids. But this led to inventor Peter Durand creating the first can from tin and iron with a patent from King George III. [1]

The first can opener was a hammer, chisel, or similar tool. Keep in mind these early cans were made of thick iron. There was no other practical way to open them, and our modern openers would probably break trying. So it wasn’t until cans evolved into thinner steel versions that the idea of an opener became possible.

Enter American inventor Ezra J. Warner. He patented the first official can opener on January 5, 1858. Remember, cans had become thinner at this point in time, and the classic hammer and chisel was no longer the only way to open them. So Warner created a can opener that cut into the lid and sawed around the rim.

In 1866, J. Osterhoudt patented the opener key, which was basically a key-shaped blade that sawed around the edge of the cans. Many canned products came with their own keys designed to open that particular item, such as tinned fish, meat, beans, and coffee. This key is perhaps the least known can opener and it is also the one that least resembles the openers we are familiar with. It’s become obsolete for the most part but if you manage to come across one, you can now recognize it for its unique part of history. 

The first all-purpose can opener appeared in 1870 when William Lyman patented the first rotary cutter. It resembled a bent bayonet with wheels operated by a crank that rolled around the edge of the can. But Lyman’s invention did not resemble the openers we use today. That design came from Charles Arthur Bunker in the 1920s. He expanded on the rotary design, but the initial piercing and wheel operation was challenging to use.

So, in 1925, the Star Can Opener Co. added a second wheel to grasp the can’s edge. This design became key in the opener you commonly see today. But in the 1980s came the “smooth edge” design that avoids jagged edges and doesn’t touch the food inside.