Can You Make a Knife out of Aluminum?


Knives have been made out of all kinds of materials for a very long time. These include steel, bronze, silver, gold, titanium, and even plastic. However, steel is by far the most dominant choice for a variety of reasons. But how about aluminum? Is it possible to make a knife blade out of it?

You can make a knife out of aluminum, however that knife would bend easily and wouldn’t hold an edge very well. Aluminum is a soft metal that deforms easily and it is also lightweight. All of that being said, an aluminum knife would only be good as a butter knife or some decorative, nothing else.

In the rest of the article I will cover the following:

  • Is aluminum a good material for a knife blade?
  • Can you forge an aluminum knife?
  • How about knife handles?

So grab some coffee and make yourself comfortable. Let’s dive in.

Is aluminum a good material for a knife blade?

Mechanically, chemically and physically, aluminum is a metal similar to brass, copper, lead, and titanium. It can be formed, cast, and melted in a similar way to these. One of the first noticeable properties is the aluminum lightweight. Namely, aluminum is an extremely light metal with about a third weight of steel. For knives, this can be very beneficial.

Aluminum is also known for its corrosion resistance as it generates a solid protective oxide coating which keeps it from making contact with the environment. This is especially important for kitchen knives. However, note that most aluminum alloys are less resistant to corrosion than pure aluminum. Besides lightweight and corrosion resistance, the ease of sharpening is another advantage of the aluminum knife.

Now, onto the bad stuff. Aluminum is a very soft metal, making it inferior for general knifemaking purposes. For a knife to be functional it needs to have a solid level of hardness to maintain the edges. It also bends easily. Aluminum is usually half the hardness of stainless steel which is obviously not enough. Chances are that the aluminum knife would lose the edge after the first use.

Aluminum knife ADVANTAGES

  • Lightweight
  • Resistant to corrosion
  • Cheap
  • Easy sharpening
  • Readily available

Aluminum knife DISADVANTAGES

  • Extremely soft
  • Bad edge retention
  • Bends easily

All in all, aluminum is not a good material for a knife blade since it is very soft and bends easily. An aluminum knife doesn’t hold the edges very well. However it is lightweight and resistant to corrosion, so it may serve as a knife that doesn’t require the use of edges.

Finally, aluminum is the most abundant metal on Earth which makes it cheap and most of the time readily available.

Can you forge an aluminum knife?

There is a lot of myths and wrong information on the internet when it comes to forging aluminum. I see some guys on forums saying it is impossible to forge aluminum. While this may be the case for cast aluminum, it is certainly not for the rolled-out bar form.

As we have already said, aluminum is a very soft metal. However just because it is soft that doesn’t mean it cannot be forged. The same thing is with copper and bronze. They are soft but they can be forged. Aluminum is no different.

Ok, so to properly forge aluminum you need the material itself, forge, hammer, anvil, tongs, and finally a finely shaped piece of pine. The aluminum should be heated up to the point when the piece of pine smokes off in the contact with the material. If it gets too hot, it will melt and drip right off. On the other hand, if you don’t heat it enough, it is just like cold working it.

It is important to note that aluminum doesn’t have a color change, so you cannot determine the temperature by just looking at it. Aluminum just goes from nice silver to molten silver. What you want is to take a nice low fire heat and check it with the pine. If the edge of the pines begins to smoke, it means you can start hammering on the anvil.

Keep in mind that forging aluminum doesn’t require intense heat. You can just place it on the top of the fire and eventually, it will get there. During the hammering, you will notice that it is soft and very similar to forging hot copper. As you keep hammering, aluminum will work hard on you and the longer you hammer it, the tougher it gets. When it gets too tough, just reheat it again and use the piece of pine as the indicator of the ideal temperature.

In case you are not sure if you have aluminum or not, one of the easiest ways to check is with the car keys. Just scratch the material and see if it leaves the mark. If it does, you probably have the aluminum.

How about knife handles?

In case you don’t want or plan to make an aluminum blade, you may think of making the handle out of it. Many knifemaker newbies fall into the trap of thinking that the knife handle is only about aesthetics. However, that is not the case. A knife handle is crucial to the overall characteristics and performance of the knife.

When it comes to knife handles, you can choose between metal, synthetic, and natural materials. Each has its own set of pros and cons, however, I will only talk about aluminum in this article.

Aluminum is known as an extremely durable material for knife handles. One of its biggest benefits is lightweight, primarily due to the low density. This allows you to have a nice feel to the knife. In terms of weight, it falls in between titanium and stainless steel.

Aluminum can also anodize into almost any color you can imagine which provides much broader style variations. If properly texturized, it will provide a comfortable and secure grip, even for a longer period.

One of the most popular types of aluminum used for knife handles is the T6-6061 alloy due to its high tensile strength. Now let’s talk about the disadvantages.

One of the downsides of the aluminum knife handle is that handle might be uncomfortably cold during the winter due to its conductive properties. Aluminum handles tend to also be slippery sometimes so keep that in mind.

If you are a beginner knifemaker, I strongly recommend using wood instead of aluminum and other materials. Wood is one of the most popular and oldest knife handle materials. It has a strong textured grain and composition which provide a solid grip and aesthetic appeal. Unlike aluminum, wood offers the most variety. Not only that wood knife handles are available in many species but they can also be easily carved into many different shapes and sizes.

Conclusion

Aluminum is a very known material in the knifemaking industry. It is mostly used for making knife handles but can also be used for forging a blade. Although aluminum may not produce the best knife blade, it can certainly serve as a butter knife or something similar. Aluminum can also be forged, despite many myths surrounding it. If you plan to forge it, make sure to get yourself a thin piece of pine that will serve as a temperature indicator. Lastly, aluminum will make a good-quality knife handle, however, it may not be the best option for beginners.

Recommended reading:

Can You Make a Knife Out of Silver?
The Definite List of Knife Making Tools for Beginners
7 Knife Making Power Tools for Maximum Productivity

Albert from Wyoming

Hi, Albert here... Forging World is the place where I share everything I've learned (and still learning) in my 20ish years of experience in forging. Hope you like the blog and #keepforging #keeplearning

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