What is 420J2 Steel?

The 420j2 stainless steel is a popular choice for knife manufacturers. 420j2 stainless steel contains medium quality carbon content. It has good corrosion resistance in salt-free atmospheres and in most industrial environments. It is resistant to many chemicals and household cleaners; and, it is also a more durable steel compared to the 440 grades.

What 420j2 Steel is Used For

This steel is used in making precision surgical instruments because of its sharpness as well as its corrosion resistance. Surgical steel needs to be treated in a very harsh environment to sanitize it. (The best folding knife for under $50 endorsed by an Airborne soldier).

The 420j2 steel is also used for making knives, daggers, and other instruments used in battle. This steel is often made into haircutting scissors and household scissors. The 420j2 steel is great for producing a fine and smooth polished blade.

Properties of This Steel

420j2 steel can be easily machined, so this increases its usefulness and demand. 420j2 has a superb hardening capability which makes it a very good all-purpose knife. The hardening process is comprised of the following steps, and these steps result is a great knife.

How it is Made

Beginning with heat treatment and sub-Critical Annealing: Heat treatment begins by uniformly heating the steel to 730 °C – 790 °C and keep the temperature there until the temperature is the same throughout the piece of steel. The next step is soaking the steel and air cooling it. Annealing involves heating the steel throughout to 840 °C – 900 °C and hold it until the temperature is the same throughout. The next step is soaking but cooling it in the furnace.

Hardening means heating it until the temperature reaches 950 °C – 1020 °C and hold there until the temperature reaches throughout the section. It is necessary to put the steel in an oil or air cooling system to reduce heat. Temper immediately while still hand touch warm. Proper hardening will result in the best all-around properties of the steel. Tempering is a process that should be done carefully. Otherwise, the critical characteristics of the steel will be damaged. There are several steps that can be taken to turn the tempered steel into material that is useful for a variety of purposes. Many knives are made from this steel. It is excellent steel for making hunting knives and general purpose household knives. Some woodcarving tools are also made of this steel.


420J2 is a great steel for certain uses. Likely, it fits your purposes perfectly!  If you enjoyed this article, check out our review of machetes. We also have super tips on how to find a great balisong knife.

Peter Stec
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  1. My Union Taiwan dive dagger is far too soft and does not take a sharp edge and looses what little sharpness I can achieve very quickly. I therefore conclude that either this steel is unsuitable for making knives and/ or it was not properly gardened.

  2. The article is nice and it’s pleasant to read. I have known very important things over here. This is the perfect blog for anyone who wants to know about this topic.

  3. Speaking of general use knives, 420JS is to be reserved for very intensif corrosion environnements. Edge retention is not as good as 420C, 440A or 440C…

    The 420JS price is low. The other option for highly corrosion resistant steels is nitrogen steels like N680 or X15TN. But the price of these steels is way higher.

  4. how does this pare up with hair cutting scissors? I mean, would it make for a good quality and sharpness?

    1. It is commonly used for hair cutting scissors. Be sure to get a good quality one.
      There is other steels with better edge rentention like 420C, 440 series, 12C27M… These rust faster.

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