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What is Stainless Steel? How can it make Apple Products Durable?

Language/语言:   English   简体中文

By: Ken Deng   Published on Sep. 20, 2021

Approx. 600 words, 3 mins

  Table of Contents

Hello there! My name is Ken and I am a Chinese senior high top student in Guangdong Country Garden School. Welcome to Ken's Study Journey website with Chemistry knowledge explanations!

Recently, iPhone 13 and Apple Watch 7 were released. Both of them are using stainless steel, which makes Apple products more durable.

Stainless steel is resistant to corrosion and very strong, so the outer shell of the iPhone 13 and Apple Watch 7 can prevent rusting and accidental cracking.

Stainless steel and uses of metals are covered in IGCSE Chemistry (0620) syllabus, so I have fully learned this knowledge.

Do you know why stainless steel plays an important role in the things we use nowadays? Let's go!

Types of Steels

First, I would like to talk about some types of steels.

Steel is an alloy made of iron (Fe) and carbon (C). Alloy is a mixture of two or more metals or one or more metals with a non-metal. The layers of alloys cannot slide very easily, so it is strong and hard.

There are 4 types of steels: mild steels, high carbon steels, low alloy steels and stainless steels.

Mild Steels

Mild steel is a low carbon steel that contains about 0.25% carbon.

It is soft and can be easily shaped, so it can be drawn into wires.

It is used for constructing buildings, bridges and vehicles.

High Carbon Steels

High carbon steels contain more than 0.5% carbon, so it is stronger than mild steels.

It is used to make some tools like hammers.

Low Alloy Steels

Low alloy steels contain 1% to 5% other metals.

It is used for high-speed tools because it is harder and its shape cannot be easily changed even if the temperature is high.

Stainless Steels

Stainless steels are high alloy steels. They contain more metals like iron (Fe), chromium (Cr) and nickel (Ni).

Because it is composed of many metals, it is very strong and is resistant to corrosion. It is used for cutlery like knives and forks, bowls and musical instruments.

Some food is corrosive, so stainless steel is used to prevent corrosion and store food securely.

On iPhone 13 and Apple Watch 7, stainless steels are used because it is resistant to corrosion and even accidental cracking. That's why they can make later Apple products more durable.

Extra Knowledge: Why Iron (Fe) Rusts?

Now, let's talk about why iron rusts without stainless steels.

Some metals can be oxidised when they are touching the oxygen (O2). For example, Aluminium (Al) can be oxidised in the air to form an aluminium oxide thin layer (Al2O3) to prevent corrosion. This kind of reaction is called: oxidation reaction.

When iron touches both oxygen and water (H2O) in the air, it can form a red rust called Iron (III) Oxide (Fe2O3). This is the chemical equation:

Iron Rusting Chemical Equation

How to Prevent Rusting?

But don't worry! There are several ways to prevent iron from rusting.

As I mentioned above, iron needs to touch both water and oxygen to rust. Without one of these things, the rust cannot be generated.

So, we can think about some ways to prevent iron from touching oxygen or water.

We can paint some oil around the iron so it cannot touch the air.

There is another way to prevent rust. We can use sacrificial protection to paint zinc (Zn) because its reactivity is higher than iron. The zinc will rust first before the iron rusts. However, this is a chemical method so it is not common in general use without this metal.


Stainless steel can make Apple products more durable because it is a strong alloy made of different kinds of metals.

Alright! This is the end of the chemistry knowledge explanation of the stainless steel on iPhone 13 and Apple Watch 7. Thanks for reading and I hope you can understand the computer science knowledge behind on new Apple products.

If you like this explanation, please click the thumb up button below and share this article. Also, you can write down your comment below if you have any ideas. I am a student so my knowledge explanations may contain errors. If it has any errors, you can contact me to correct them.

Still have questions or cannot understand my knowledge explanations? Don't be hesitant to contact me and I am here to help you. I speak English and Chinese.

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