If you are a collector or just another person interested in buying the best cookware or jewelry on the market, you might want to make sure that you know to differentiate the items you see online or on the store’s shelf. On top of our list of the most confusing metals, we have stainless steel and aluminum.
These two take the top spot because we cannot count the number of times we’ve been confused by the two metal pieces, and even duped.
To ensure that your next project, jewelry or cookware set is made of exactly the materials you dreamed, this article is dedicated to differentiating stainless steel from aluminum.
How is Stainless Steel Different from Aluminum?
1.Strength and Weight
The lightweight of aluminum is the reason why items made of aluminum tend to be malleable and flexible. Thanks to the softness and the malleability of aluminum, you will find aluminum in aircraft and ships while stainless steel is common in road constructions and other heavy-duty applications.
Note, however, that despite the low strength or the lightweight design of aluminum, aluminum boasts a significantly higher weight to strength ratio compared to stainless steel (and really, just about every other metal out there).
This high weight to strength ratio means that despite the lightweightedness of aluminum, it holds a lot more weight when than stainless steel. A piece of aluminum weighing the same as a piece of stainless steel is up to three times more powerful than stainless steel.
No one wants to buy a piece of metal that corrodes upon exposure. Looking at stainless steel and aluminum, stainless steel has a significantly higher level of corrosion resistance than steel.
This resistance is because of two main reasons: stainless steel is made of at least 10% chromium which will react chemically with oxygen in the air to form an invisible layer of a corrosion-resistant film all around the piece of steel.
The other reason for stainless steel’s corrosion resistance has to do with the fact that the stainless steel metal is naturally non-porous meaning that nothing gets in or out, hence the resistance to corrosion.
On the other hand, you have aluminum which has a significantly high rate of oxidization, and it’s also corrosion-resistant.
However, it’s susceptible to corrosion because its oxidization initiates a chemical reaction between aluminum and oxygen, forming a thin layer of aluminum oxide.
The aluminum oxide layer is white. Though largely protective, this white film will, over time, form pits and small holes on the surface of the aluminum material. These holes cause corrosion over time.
The other difference between stainless steel and aluminum lies in the conduction of heat.
Aluminum is a great conductor of heat, hence its use in air conditioning units and car radiators.
On the other hand, stainless steel has poor conductivity. But there’s a catch – stainless steel has a higher rate of thermal conductivity at higher temperatures than aluminum, which is why you can use stainless steel at high temperatures exceeding 800 degrees.
At this temperature (or anything generally above 400 degrees), aluminum gets soft.
Aluminum has a very high electrical conductivity, while stainless steel has low electrical conductivity.
As a result of aluminum’s lightweight design, great conductivity, high weight to strength ratio, as well as its corrosion resistance, aluminum is commonly used for overhead electrical cables.
The other big difference between stainless steel and aluminum lies in their workability or flexibility. Because of the softness and the malleability of aluminum, it’s a lot easier to cut and mold aluminum than stainless steel.
Stainless steel is, as mentioned previously, harder/stronger than aluminum, which is why it’s harder to mold or carve stainless steel parts. For example, you cannot resize jewelry made of stainless steel.
6.Use and Reactivity Around Food
If you wish to tell whether the cookware you are using is stainless steel or aluminum, check the reactivity to food. Stainless steel is less reactive to food compared to aluminum, and aluminum could alter the color, taste/ flavor of your food.
The color of stainless steel, aluminum, and silver looks the same, so I also write this post: how to tell the difference between silver and stainless steel?
How to Tell if Something is Stainless Steel or Aluminum？
Besides reacting to tomatoes, you can also tell whether the metal you are dealing with is stainless steel or aluminum by running some tests:
Step 1 – The Key Test
For this test, get your car key or any other key around you and then press it down and drag the key along the test sample’s flat surface.
If the questionable piece is made of aluminum, there will be a fair amount of scratching with little pressure applied. The reason for this is that aluminum is soft. On the other hand, if the questionable piece is made of stainless steel, there will be scratching on the flat surface, but you will need to apply a significant amount of pressure for the scratches. Also, the scratches will not be very deep.
Note that this test is a bit cringy, and that weird and unpleasant feeling or sensation on/ in your teeth is called Grima.
Step 2 – The Magnetic Test
For this test, you require a strong magnet such as the rare earth magnet, neodymium.
If the questionable item is aluminum, it will not be attracted to the magnet. But if you are dealing with stainless steel, there will be some magnetic attraction.
It’s definitely stainless steel if it’s heavy, and aluminum if it’s lighter.
Aluminum costs a lot less than stainless steel.
If you are testing cookware, you can tell whether the piece you are handling is made of aluminum if:
- Warm/ cold– If the pot feels slightly warmer on the touch, at room temperature. Stainless steel feels colder at room temperature.
- Sound– if you bang aluminum using a wooden spoon, it will produce a dull sound, but the sound from a stainless steel pot will be louder.
- Cleaning/ Dullness– Aluminum dulls, albeit slightly, after washing while stainless steel keeps shining even after washing.
Aluminum and stainless steel might look so much alike, but using the tests above, you can differentiate them with ease. if you guys want to know more about How to Tell If Stainless Steel Jewelry Is Real? (In a Right Way) You guys can read this post.