431 Stainless Steel vs 17-4 – What’s the Difference

431 Stainless Steel vs 17-4

When choosing the right type of stainless steel for your project, the task can be overwhelming. With so many alloys available, knowing where to start can take time. In this blog post, we will compare two popular types of stainless steel: 431 and 17-4. By the end of this article, you will have a better understanding of the differences between these two alloys and which one is the best choice for your specific project.

Difference Between 431 Stainless Steel and 17-4 Stainless Steel

Chemical Composition

The main difference between 431 and 17-4 stainless steel is their chemical composition. 431 stainless steel contains about 17% chromium and 2% nickel, while 17-4 stainless steel contains about 17% chromium, 4% nickel, and 3% copper. This composition difference affects each alloy’s properties, which we will discuss in the following paragraphs.

Corrosion Resistance

Both 431 and 17-4 stainless steel are capable of withstanding corrosion. However, due to its higher nickel and copper content, 17-4 has better corrosion resistance in harsh environments. 431 stainless steel is better suited for applications where mild corrosion may occur, such as in food processing equipment.


Many applications require high-strength materials, and 431 and 17-4 stainless steel fit the bill. However, 17-4 stainless steel is stronger due to its higher nickel and copper content. This makes it an ideal material for applications such as aerospace parts, industrial equipment, and shafts.


Machinability is an important factor to consider when choosing a stainless steel alloy. 431 stainless steel has good machinability, making it easy to work with and machine. On the other hand, 17-4 stainless steel can be more difficult to machine due to its higher strength and hardness. However, it can still be machined effectively with the right tools and techniques.


Finally, cost is always a concern when choosing a material for your project. 431 stainless steel is generally less expensive than 17-4 stainless steel due to its simpler composition. However, remember that each alloy’s specific cost will depend on many factors, such as quantity, size, and supplier.


Choosing the right stainless steel alloy for your project is essential to achieving the desired results. In this article, we compared the properties of two popular alloys, 431 and 17-4, and highlighted their differences. By considering factors such as corrosion resistance, strength, machinability, and cost, you can decide which alloy is the best choice for your specific application. Consult a knowledgeable supplier or engineer to ensure you choose the right material for your project.

Harsh Jain

Harsh Jain

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