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420 Stainless Steel

420 is martensitic stainless steel that provides good corrosion resistance similar to 410 plus increased strength and hardness.

420 stainless steel

420 Stainless Steel

420 stainless steel is a martensitic higher carbon version of types 410 and 416 stainless.

Type 420 stainless steel, also known as martensitic steel, is a type of steel that offers good corrosion resistance similar to that of 410 stainless steel.

However, it also provides the added benefits of increased strength and hardness.

This type of steel is magnetic in both its annealed and hardened conditions, making it a versatile option for a wide range of applications.

Some common uses of 420 stainless steel include cutlery, surgical and dental instruments, straight edges, and firearms.

At our company, we are proud to offer Type 420 in bar, wire, and billets form, and we strive to provide our customers with the most competitive prices on the market.

420 stainless steel has a long history of being a reliable and durable alloy. Its unique combination of hardenable properties and high carbon content have made it a preferred choice in various industries, and its popularity continues to grow as engineers and researchers continue to improve and modify the alloy to meet the demands of new applications.

We are dedicated to ensuring that our clients have access to the highest-quality materials, so if you have any questions or would like to place an order, please do not hesitate to contact us.

420 Stainless Steel Properties and Specifications

420 stainless steel, a hardenable martensitic alloy, boasts corrosion resistance similar to that of Type 410. Its higher carbon content elevates its strength and hardness when compared to Type 410.

To achieve maximum corrosion resistance, 420 stainless steel must be fully hardened or fully hardened and stress relieved. It should not be used in annealed condition.

420 stainless steel is available in:

  • Bar
  • Wire
  • Billets

Type 420 Stainless Steel (bar, wire, and billets) is covered by the following specifications:

  • QQ-W-423A
  • MIL-S-862B
  • MIL-S-8142
  • MIL-W-17481A
  • AMS 5621
  • ASTM A276-67
  • ASTM A314-63
  • ASTM A580-67
  • QQ-S-763D

What is 420 Stainless Steel?

420 stainless steel, commonly known as martensitic stainless steel, is a hardenable alloy with excellent corrosion resistance. Because of its capacity to tolerate extreme environments and resist wear and tear, it is a popular choice in a variety of industries.

One of the most distinguishing features of 420 stainless steel is its high carbon content, which allows it to have greater strength and hardness than other varieties of stainless steel. This makes it excellent for high-strength applications such as cutlery, surgical tools, and pump shafts.

Another advantage of 420 stainless steel is that it may be thoroughly hardened, increasing its resistance to corrosion. This is especially beneficial in applications where the alloy will be subjected to hostile chemical conditions or excessive temperatures. It is vital to note, however, that it should not be utilised in an annealed state, as this can affect its corrosion resistant qualities.

History of 420 Stainless Steel

The history of 420 stainless steel dates back to the early 20th century when it was first developed by engineers looking for a strong and corrosion-resistant alloy. It was created by combining martensitic stainless steel, which is known for its hardenable properties, with a higher carbon content to increase its strength and hardness.

It was initially used in cutlery and surgical instruments, as it was able to withstand the demands of these applications and resist wear and tear. The alloy quickly gained popularity in other industries as well, such as aerospace and marine, due to its strength and corrosion resistance properties.

Over the years, 420 stainless steel has undergone various improvements and modifications to enhance its properties and make it more suitable for a wide range of applications. Today, it is widely used in various industries such as food processing, medical, aerospace, and marine among many others.

What are the uses for 420 stainless steel?

420 stainless steel is a versatile alloy that offers high strength, hardness and corrosion resistance making it suitable for a wide range of applications. Due to its properties, it is a preferred choice for industries such as food processing, medical, aerospace, and marine among many others.


420 stainless steel is a versatile alloy that offers high strength, hardness and corrosion resistance making it suitable for a wide range of applications.

Due to its properties, it is a preferred choice for industries such as food processing, medical, aerospace, and marine.


Because of its great strength, corrosion resistance, and sterilizability, it is a popular material for surgical instruments such as scissors, scalpels, and forceps.

The alloy retains its sharpness and strength even after repeated sterilisation and use, making it dependable and long-lasting.

Pump Shafts

420 stainless steel is used in pump shafts due to its high strength and corrosion resistance, allowing it to withstand high stresses and harsh chemical environments.

It resists corrosion and wear and tear, making it a cost-effective option in the long run as it reduces the need for frequent maintenance.


Its high strength and corrosion resistance properties make it a suitable choice for aerospace applications such as landing gear and fasteners.

The alloy is able to withstand the extreme temperatures and pressures of high altitude flight, making it a reliable and safe option for aerospace manufacturers.


420 stainless steel is frequently used in marine applications such boat fittings, propellers, and shafts because to its resistance to corrosion and high strength.

Type 420 is a tough and affordable choice for maritime producers since it can survive the severe saltwater environment and resist rust and corrosion.

Food Processing

Due to its non-toxic and corrosion-resistant qualities, it is a favoured option in the food processing industry for applications including storage tanks and food processing machinery.

It is a safe choice for food contact; it can withstand corrosion and rust. It is also hygienic for food processing operations, as it is simple to maintain and clean.

420 Stainless Steel Composition & Properties


Type 420%


.15 max


1.00 max


1.00 max


.040 max


.030 max


12.0 – 14.0

Mechanical Properties




Stress Relieved

Ultimate Tensile Strength, psi



.02% Yield Strength, psi



Elongation, % in 2?



Rockwell Hardness




Reduction of area, %



Impact Strength Izod   V-Notch, ft-lbs





420 Stainless Steel Heat Treatment

Corrosion Resistance


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