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Any fan of Japanese knives must have come across HAP40 steel. It is one of the preferred steel in the U.S. market due to its toughness and durability. Many regard it as the most innovative steel from Japan.

HAP40 is typically seen in high-end chef knives made in Japan. You can even find it in some high-end pocket knives from Spyderco as well. Let’s explore its chemical composition, properties, and performance compared to its peers.

What is HAP40 Steel?

Yoshihiro HAP40 High Speed Stainless Steel Kiritsuke Multipurpose Chefs Knife Ebony Handle (10.5'' (270mm))

HAP40 is a powdered high-speed tool steel from Hitachi Metals Ltd. It is made using the Powdered Metallurgy (PM) process. It is also high-carbon steel and boasts an ideal balance of toughness, hardness, and edge retention.

Its composition and fine microstructure make this Japanese steel an excellent material for making knives. It is used for manufacturing cleavers, chopping knives, utility knives, paring knives, and all-purpose kitchen shears. Knife users consider it an excellent choice when it comes to handling much beating or damage.

Chemical Composition

This tool steel has less than 13% of chromium required for being stainless. Below are the constituents of this Japanese tool steel:

  • 1.27-1.37% Carbon: For improved strength, hardness, and resistance to wear
  • 3.70-4.70% Chromium: For improved toughness, tensile strength, edge retention, hardness, and resistance to corrosion
  • 5.60-6.40% Tungsten: For improved steel strength, hardenability, and toughness
  • 4.60-5.40% Molybdenum: For improved hardness, hardenability, and toughness
  • 2.80-3.30% Vanadium: For improved wear resistance, toughness, and strength
  • 7.50-8.50% Cobalt: For boosting the individual impact of all the above constituents

Bohler’s Vanadis 30 is similar to HAP40 steel in terms of chemical composition. The former also contains carbon, chromium, tungsten, vanadium, molybdenum, and cobalt. Thus, even Vanadis 30 belongs to the category of high-speed tool steels. Just as the Japanese steel, it is also made using PM technology. Both are known to deliver an ideal blend of toughness, edge retention, and corrosion resistance.

Hardness

On the Rockwell scale, HAP40 has a rating of 64 to 67 HRC, the exact value differs as per the type of heat treatment given. This range indicates an extremely high level of hardness. The credit for such hardness goes to the fine microstructure and rich chemical composition.

Steel Properties

Chef Knife, Chef Kitchen Knife Japanese HAP40 Steel Fish Filleting Professional Kiritsuke Sashimi Sushi Gyuto Knives with Octagon Handle BY KKZY (Kitchen Knife Size : 8 inch)

  • Great Toughness: Because of its chemical composition it strikes a good balance between hardness and toughness. This steel is admired for its great toughness, contributed by tungsten, cobalt, vanadium, and molybdenum. This is one of the rare steels that are tough despite being very hard. The knives will not chip, crack, or break easily when exposed to hard use.
  • Edge Retention: Many regard HAP40 as the best Japanese steel in terms of edge retention and cutting performance. This is attributed to its high hardness level, and chromium content. You can rely on your HAP40 knife for lots of cutting without stropping for several days.
  • Great Wear Resistance: You can expect this steel to have great wear resistance, because of its high hardness level. Again here, the ideal mix of all elements in the chemical composition is responsible.
  • Poor Corrosion Resistance: As there is little chromium in the chemical mix, it is not as good as stainless steels when it comes to corrosion resistance. Nowadays, the makers are laminating HAP40 knives with anti-corrosion and stainless finishes to keep rusting and corrosion away. Keeping your HAP40 knife clean and dry and oiling it can also prevent rust from attacking its blade.
  • Ease of Sharpening: It is not that easy to sharpen an edge of this steel. This is not surprising considering its hardness and great wear resistance. However, if you use the right sharpening stone, it will easily render a hair-splitting edge. This is possible because of its fine microstructure.

Comparison With Other Knife Steel Options

HAP40 vs ZDP189

Both belong to the family of high-carbon steels. However,  HAP40 beats ZDP189 in terms of toughness.  It is also easier to sharpen and gain an ultra-sharp edge than ZDP189.

Although HAP40 is admired for great edge retention power, ZDP189 is known to hold its edge for longer. It is also better at resisting corrosion due to more chromium content.

HAP40 vs VG10

HAP40 is tougher and easier to sharpen than VG10. On the other hand, VG10 is stainless steel and is better at resisting corrosion.

HAP40 vs S30V

S30V is stainless steel, while HAP40 is a carbon tool steel. So, when it comes to resisting corrosion, S30V is a better choice. It is also more readily available because it is made in the US. S30V is easier to sharpen as well. But, the Japanese tool steel will hold a sharp edge longer.

Top HAP40 Knives on Amazon

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So, is HAP40 a Good Knife Steel?

With its great toughness, high hardness, and excellent edge retention properties, HAP40 is preferred usually for big knives. It will not chip or break easily. The area where this knife lacks is corrosion resistance, because of low chromium content. Hence we recommend getting knives with anti-rust coating.