How to Open a Can With a Key?

How to Open a Can With a Key

The preservation of food using can was practiced as early as 1772 in the Netherlands. However, the first can opener was patented in the 1850s. In the ancient past, every can came with a key to open it attached on top. The young generation may find it difficult even to figure out how the key opens the can. The can key a classic method of opening cans that were square in nature until the invention of pop-top.

There are various types of can openers, although they come with keys attached to them. For ease of classification, they are categorized as different types of openers. Several items can replace keys to open cans. Some of the items are crudes such as spoons, pocket knives, garage tools, and Chef’s knife.

To open the can using the key attached, all you needed to do was remove the key and insert it into the hole on the can’s flank. As you twisted the key in the strip’s opposite direction, it tore the can away from itself, rolling the aluminum with the key.

Since there was an assurance of another key coming with every purchase of a can, one would throw away the key with the aluminum scrapings away with the can. This method of opening the can was expected and very common before the 1970s. The most common packaging in cans was frozen strawberries. Corned beef, bacon, nuts, and ham, among others.

How to use a church-key can opener?

The church-key history dates back to 1892 as a simple hand-operated device for prying the cap off a glass bottle. Nevertheless, the first church key was patented in Canada in 1900.

The use of a church key was more of a bottle opener than a real key to rip off a can. Church keys are typically used to remove bottle caps and make holes in flat-top cans. One advantage of the church key is the dual opening sides. On one side, it is a bottle opener, while on the reverse side, a triangle–shaped point with a tiny metal tab on the inside for opening cans.

Church key openers’ best suited the cans that contained liquids like the condensed milk and beer cans. Considering that liquids were involved, a steady hand was required to avoid spillage while using the key type. However, even with unsteady hands, the experience was much better than the original can key.

To use the church key opener, you must place the upper part of the triangle-shaped tip on the can’s top quota. Upon fitting the opener against the top lip of the can, press upwards. This procedure created a downward force against the top of the can.

When a triangular-shaped hole was poked, one would move slightly over and poke additional holes all-round the can. Finally, by inserting the top of the triangle piece and pulling the perforated top cover of the can upwards, the weak bonds between the holes would give in and rip-off open.

The last part of the opening that required pulling upwards would cause spillage if the operators were not careful. For liquid contents, the risk was even higher though the opener was still highly preferred over others.

Also read:How to Use a Manual Can Opener with One Wheel?

Open can with key

Not every key is suitable to be used as a can opener. A special key for the purpose of opening the can was attached to every can you got. It is, however, not new to use normal keys as crude can opener for the can that had no keys attached. Normally, the cans were quite thin and easier to open with the provided key.

Most cans will have different type of a key both in shapes and sizes. However, most of the keys use the same technology of removing a strip around the can, enabling the can’s opening. Very little energy is required while opening the can with a key.

On a closer health look, opening the can with a key reduces the risk of food contamination. The old can openers made perforation of the can and came into contact with the can content while opening. The fact that the cutter touched the food inside called for a lot of hygiene which may be questionable in stressful circumstances, like in military duties.

A disposable key ensures an improved level of hygiene and an almost effortless opening of the can. Whoever came up with the idea of a key needs a part on the back!

Also read: How to Use an Old Fashioned Can Opener?

Sardine cans with key

Like normal cans that have a key attached to them, sardine cans also come with a key attached. Most of the canned food was too expensive for ordinary citizens and a reserve for the army. It is there true that most of the civilians were not familiar with many of the old can openers. Sardines were mostly used for packaging kinds of seafood.

Sardine cans are characteristically rectangular shaped. A key to open the can was attached on the lower side of the can. To open the can, you need to remove the key from the bottom side of the can. On one side of the can, towards the top, there is a strip attached. The Sardine can key has an eye like that of a needle on one end. You are supposed to insert the strip through the key eye. Once the strip is inside, you would roll the key. When performing the procedure, the strip gets detached from the can and raps on the key opening the can.


There are great forgotten moments that rekindle great times and the history of fantastic tools like openers. As much as we enjoy the easy-to-use new-fashioned can openers, keeping yourself abreast with the old technology of can opening is important.

There is a need to understand how to open cans that come with different keys depending on the can type. The art of opening especially using a key, is so effortless, unlike using the other types of can openers.

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