A Comprehensive Guide on AISI 420 Stainless Steel

AISI 420 Stainless Steel

If you need steel that is easy to maintain and extremely strong, stainless steel is the way to go. This material has numerous advantages and can be used for various purposes. On the other hand, if you specialize in the production of medical equipment, cutlery, fasteners, or screens, AISI 420 is your best option when deciding what type of stainless steel to use. 

Typically, when determining which type of steel to use and which to avoid, it is always vital to consider the steel’s composition. This is so that you can figure out or estimate the prospective mechanical properties of a finished steel product. 

Therefore, if you’ve ever thought of choosing AISI 420 Stainless Steel but are unsure if it is the right fit, then you should read this article to the end.

Understanding AISI 420 Stainless Steel

AISI 420 stainless steel is a stainless steel variant that is especially renowned for its longevity and strength. It has several other properties, including heat resistance and magnetism in hardened and non-hardened conditions – all of which are due to its varying alloy elements.  

What is the AISI 420 Stainless Steel?

AISI 420 Stainless Steel is a type of steel belonging to the 400-grade stainless steel series composed of high-carbon and low-chromium. You can consider it a modified grade 410 stainless steel with higher carbon content. 

The abbreviation “AISI” refers to the American Iron and Steel Institute; a non-profit organization in charge of publishing and creating the specifications for making steel in the US. Hence, the designation 420 refers to the defined composition of this specific stainless steel alloy, which contains 0.15–0.40% carbon, 12–14% chromium, and the occasional addition of other elements.

It is occasionally alloyed with additional elements like molybdenum, nickel, or vanadium to give it superior corrosion resistance, high hardness, and good ductility. It has a well-deserved reputation for quality, and you might think of it as the workhorse of the steel industry.

Composition of the Steel

Composition of the Steel

Given its precision, AISI 420 Stainless Steel is employed in numerous industries. Below, a thorough analysis of these compositions is taken into account. 

Chemical Composition

AISI 420 comprises Chromium, Carbon, and other elements, with iron balancing it.

The metal variant has a reputation for strength and good hardness due to its high carbon content, and its carbon atoms combine with iron to create a strong, crystalline structure that can withstand wear and deformation. Nonetheless, it should be noted that the precise chemical composition changes based on the product’s shape and producer. 

Heat Treatment

To provide the best possible microstructure and mechanical qualities for an AISI 420, a sequence of carefully regulated annealing, hardening, and tempering operations is used.

It is fully annealed between 815°C and 900°C, followed by air or a slow furnace cooling. A temperature between 925°C and 1010°C is ideal for hardening. After that, the oil is quenched, and the air is cooled. Tempering is done next to increase the metal’s current hardness. About 400°C to 580°C are used in this technique.

Mechanical Properties

The mechanical property of an AISI 420 is highly dependent on its heat treatment and chemical composition. While it has a high hardness rating typically ranging from 50-55 HRC, it has an excellent tensile strength ranging from 1000-1600 MPa. Although it is not as malleable as austenitic stainless steel alloys, it has a reasonable level of ductility and a strong ability to absorb energy without fracturing.

Corrosion Resistance

It has good resistance to steam, air, water, hot gasses, and mild acid. In particular, when it is fully hardened, its resistance to dietary acids is higher and generally increased. It is less corrosion-resistant than ferritic grades like 430 and austenitic with higher chromium contents.

HRC of AISI 420 Stainless Steel

The Rockwell Hardness Scale (HRC) for AISI 420 stainless steel is also referred to as “Rockwell C,” where “C” stands for “hardness” and “HR” for “Rockwell.” It describes the scale used to calculate the depth to which a steel ball or diamond cone can be inserted into the surface of the tested material.

The usual HRC range for AISI 420 stainless steel is 50–55 HRC. This results from the alloy’s martensitic structure and carbon content, giving it exceptional strength and wear resistance.

Types of AISI 420 Stainless Steel

Steel Bolt and Nut

There is a large variety of AISI 420 stainless steel due to its various compositions and characteristics. Among them are:


This variety of AISI 420 stainless steel has a lower carbon content than other types, with a carbon composition of 0.15% and chromium of 12%.


With a carbon content of 0.26% and a chromium content of 12%, this type of AISI 420 stainless steel has a lower nickel content than other AISI 420 stainless steel but a higher carbon content than AISI 420A. AISI 420B is typically used in applications requiring high hardness and wear resistance. 


This variant comes with a 12% chromium content and only 0.35% carbon. It has arguably the highest chromium content among all variants, making it especially durable. Because of the need for extremely high hardness and wear resistance in applications, including cutting tools, surgical instruments, and ball bearings, AISI 420C is frequently utilized in these fields.

AISI 420J1

This type of AISI 420 stainless steel type contains 0.16% carbon, 13% chromium, and less nickel. It is more corrosion-resistant than AISI 420A because it contains more chromium. Applications that call for moderate hardness and corrosion resistance, such as knife blades and cooking utensils, frequently use AISI 420J1. 

Applications of AISI 420 Stainless Steel

AISI 420 stainless steel comes in different applications, with use in the following industries and more:

Aerospace and Defense


Given its durability and capacity for withstanding extremely high temperatures, many airline manufacturers and defense contractors use this stainless steel variant. 

AISI 420 stainless steel is used in making jets, engines, and other critical components that can support the landing aircraft’s weight.

Medical Devices

AISI 420 stainless steel is chosen to produce a wide variety of medical equipment, including surgical and dental tools, due to its ease of cleaning and resistance to corrosion.

Manufacturers use it to make MRI scanners, steam sterilizers, scissors, and more. They also use AISI 420 stainless steel in developing surgical implants and prosthetics, down to components like plates and joint pins.

Food Processing

Over the years, food manufacturers have used AISI 420 stainless steel increasingly in their processes. 

Unlike other metals that rust when exposed to moisture, AISI401 stainless steel holds its own easily. With its considerable chromium content, it easily resists corrosion and ensures the long-term quality of food processing equipment. 

Cutlery and Tools

Another direct benefit of AISI 402’s corrosion resistance is its use in making cutlery and flatware. Manufacturers use it to ensure that their products are strong and durable, while still preserving physical appeal.

Oil and Gas Industry

The oil and gas industry extensively uses AISI 401 due to its corrosion resistance. Unlike other metals, it would not rust and fail when exposed to the extreme circumstances of oil and gas drilling, lowering the danger of potential environmental failure. Furthermore, it can survive the high temperatures and pressures typical of oil and gas drilling.

Advantages of AISI 420 Stainless Steel

Stainless steel pipe


You would think its corrosion resistance and durability properties would make it expensive, but the reverse is the case. AISI 420 stainless steel is cost-effective compared to other high-end stainless steel grades, making it an attractive option for manufacturers looking to balance cost and quality. 

Easy to machine and fabricate

AISI 420 stainless steel is easy to machine – making it a great option for manufacturing precision applications. Its durability and ease of work make it an ideal material for making aircraft, vehicles, and more.

Long-lasting and durable

With its seamless combination of durability and corrosion resistance, AISI 420 stainless steel works easily for industrial applications. 

High corrosion resistance

AISI 420 stainless steel doesn’t rust, even in high-moisture situations. It can be used in outdoor and indoor applications with different pressure and temperature extremes because of this. The metal’s chromium generates a thin coating to protect steel from oxygen.

Easy to clean and maintain

As one of the most hygienic materials, this stainless steel variant is also appropriate for culinary and medical applications. You can easily clean AISI 420 stainless steel with an all-purpose cleaner and get back to work. Easy peasy!


Selecting stainless steel might be quite a task, but you don’t have to deal with the difficulty of making the choice. 

You can contact us for support and guidance on getting the best deal on AISI 420 stainless. Our agents are always available to attend to your inquiries. 


Is 420 a good stainless steel?

Yes, AISI 420 is good stainless steel. It’s corrosion resistance and durability make it perfect for use in different industries.

One Stop Stainless Steel Supply.

Whether you need stainless steel materials for your business or fabrication projects, TuoLian is your best supplier. You can find all types, grades, and thicknesses based on your needs. Guaranteed that we provide the best quality at a reasonable cost.
Update cookies preferences
Scroll to Top