420J2 steel is a low-end, general-purpose stainless steel from the 400 series. It is also referred to as 420B. This steel contains medium amounts of carbon and high amounts of chromium in its composition, making it high in corrosion resistance and easy to sharpen hence its popularity in knife making.

420J2 steel is used to make surgical knives, diving knives, barber or hairdresser shears, and budget knives for both outdoor and kitchen use. Initially, 420J2 stainless steel was not supposed to make blades, but with time, knife makers discovered it because it was affordable.

There is an assumption that it is tool steel because it is used to make surgical tools. However, 420J2 is only used to make surgical equipment because it has high corrosion resistance and is easy to work with.

420J2 Steel Chemical composition

  • Carbon C 0.36%: Increases the edge retention, hardness and tensile strength. It also improves steel resistance to wear, abrasion and corrosion.
  • Chromium Cr 14.00%: Chromium Increases hardness, tensile strength and toughness of the blade.
  • Nickel Ni 1.00%: Adds Toughness to the blade.
  • Manganese Mn 1.00%: Increases Hardness and brittleness.
  • Silicon Si 1.00%: Increases strength and heat resistance.
  • Phosphorus P 0.04%: Improves machinability and hardness.
  • Sulfur S 0.03%: Improves machinability.

Properties of 420J2 steel

420J2 Steel Hardness

Because of the low carbon content in its composition, 420J2 is not hard steel. It records a maximum hardness of 56 HRC with proper heat treatment.

Compared to other steels in the 400 series, 420J2 has the lowest hardness making it very cheap.

420J2 Edge retention

420J2 steel performs poorly in edge retention because of the low carbon content in its composition. However, there are poorer steels in edge retention on the market, so do not assume that you are buying the poorest knife.

Since it becomes dull very fast, harm yourself with the right sharpening tools and prepare your mind for frequent knife sharpening.

420J2 Steel Toughness

Steel can either offer you incredible hardness or toughness. With the steel of the day, it offers admirable toughness because of its low hardness. You can be sure that knives made from 420J2 steel will never chip or break when subjected to the pressure of hard applications.

420J2 Steel Corrosion resistance

420J2 offers excellent corrosion resistance because of the high levels of chromium in its composition. If you are on the market for a knife to use in corrosive conditions, 420J2 knives will never disappoint you. It is because of the high corrosion resistance that 420J2 is used in the manufacture of surgical and dive knives used in corrosive environments.

Sharpening 420J2 Steel

420J2 is soft steel; hence sharpening it is easy. It gets sharp as fast as it loses its edge. Maintaining knives made from this steel is easy because you do not have to spend a lot of time and effort attaining an edge that will be lost quickly.

420J2 Machinability

420j2 steel is easy to mold and work on than other steels in the 400 series. A rule of thumb in steel is that you can only get a tough blade if it was easy to mold, which is true with 420J2.

With the easy machinability and affordability, 420J2 steel remains the first option for knife makers targeting low-end blades.

420J2 steel equivalent

420J2 vs 440C

Both steels belong to the 400 series, making them cousins. Grade 440C steel contains higher amounts of carbon, giving it more hardness and better edge retention. On the other hand, being soft steel, 420J2 gives more hardness and better corrosion resistance than 440c.

420J2 vs VG10

VG10 Steel is widely known for its easy machinability, but it cannot beat the machinability of 420J2 which does not come with high hardness. Both steels make beautiful blades, but VG10 is more expensive. Knifemakers who prefer easier metals to work on should lean more on 420J2.

Is 420J2 Steel Good for Knives?

420J2 is a good steel for knives, especially knives, to be used in highly corrosive environments because it scores best in corrosion resistance. What’s more, it is tough, easy to sharpen, and affordable, giving you a quality knife at its level at an affordable price.

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