ZDP-189 aka MC66 Steel: Is it a Good Knife Steel?

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Steel grades used for making knives are available at various tiers. You will always end up paying more for what specialists call super steels. ZDP-189 is one such steel from Japan. Spyderco has a large array of knives with blades made of this steel. This itself is an indicator of quality.

What is ZDP-189 Steel?

Yoshihiro Hayate ZDP-189 Super High Carbon Stainless Steel Nakiri/Usuba Vegetable Chef's Knife 7"(180mm) Premium Ebony Handle with Sterling Silver ring

ZDP-189 is a Japanese premium steel. Made by Hitachi using the Powder Metallurgy technology, this steel is known as one of the hardest steel options available for making knives.

It is known for its durability and extremely hard properties. Thus, it is often used to produce high-end custom knives. It is used also in making premium EDC as well as kitchen knives, survival knives, and surgical blades.

Top brands such as Kershaw and Spyderco are using this super hard steel in some of their knives. Even Henckels uses this steel but has given it a codename as MC66 steel.

MC66 Steel Chemical Composition

ZDP-189 has a whopping 3% Carbon, which indicates how hard as well as superior this steel is. It is costly to manufacture steel with such a high Carbon amount. Similarly, it features high chromium content enough to be categorized as stainless steel.

Here is the chemical composition of this super steel:

  • 3% Carbon: For greater hardness as well as resistance to wear and corrosion than normal
  • 20% Chromium: For extreme tensile strength, toughness and hardness, edge retention, and resistance to corrosion and wear
  • 1.4% Molybdenum: For higher strength as well as resistance to corrosion than usual
  • 0.6% Tungsten: For improved hardness as well as wear resistance
  • 0.5% Manganese: For improved wear resistance, hardenability, and forgeability
  • 0.4% Silicon: For more strength
  • 0.1% Vanadium: For more toughness as well as wear resistance

In terms of chemical composition, It is similar to Cowry X. They both have the same percentage of Carbon and Chromium. However, ZDP 189 contains extra constituents such as Tungsten, Vanadium, and Molybdenum.

Even Bohler’s M390 is very close. It has all the constituents of ZDP 189, and even the Chromium percentage is the same. However, it has only 1.9% Carbon content. Thus, ZDP-189 is superior in terms of hardness, although both are in the same price range.

Steel Hardness

On the Rockwell scale, the hardness rating of ZDP-189 is 65 to 67HRC. This is a very high range, and it is not likely to be found for steels used in mass knife production. The credit for such an incredible range of hardness goes to the mix of high carbon and chromium.

The typical level is around 64 HRC. However, a few manufacturers can boost it to 66 HRC by giving a distinct heat treatment. Right now, this is perhaps the hardest steel used for knives. While some exotic options can be harder, this steel is found more easily.

Steel Properties

Spyderco Endura 4 Lightweight Signature Folder Knife with 3.80" ZDP-189 Steel Blade and British Racing Green FRN Handle - PlainEdge - C10PGRE

  • Relatively Low Toughness: As this steel is too hard, its toughness level is somewhat lower than many knife steel. As a rule, the harder a steel grade, the lower is the level of toughness. For knife users, what this means is this Japanese steel will not be the best option to keep chipping or breaking at bay. However, its toughness is good enough to handle hard tasks without breaking. It is used in making knives for camping and surviving.
  • Incredible Edge Retention: If you have ever been disappointed with the quick dulling of your knife blades, you will rejoice with this steel blade. A ZDP-189 knife comes with a superior cutting edge, which retains its sharpness for a long time even if used for tough cutting jobs. It will neither deform nor become dull. The credit goes to the extreme hardness level of this steel.
  • Excellent Wear Resistance: The high level of hardness always contributes to excellent wear resistance.  ZDP-189 is no exception. The high Carbon, as well as Chromium amounts, take wear resistance to a new level. You can truly pass your knife on to your next generation.
  • Great Corrosion Resistance: With 20% Chromium, this steel effectively keeps corrosion as well as rust at bay. Nevertheless, some cheaper steels resist corrosion better. This is because of the higher carbon content in ZDP-189.
  • Ease of Sharpening: Due to unparallel hardness, ZDP-189 is difficult to sharpen. This is the common drawback of all super and premium steels having a high level of hardness. Still, you can get a super-sharp edge, but you will need an advanced sharpening system and spend more time and effort than usual.

Comparison With Other Knife Steel Options

ZDP 189 vs. S30V

The latter is a premium option with a good balance amongst its properties. However, ZDP 189 is far better than S30V when it comes to retaining a sharp edge, while S30V is better at resisting corrosion. It is easier to sharpen an S30V edge, though. In terms of toughness, both of them offer similar performance.

ZDP 189 vs. S110V

The latter by Crucible is an ultra-premium option. It wins over ZDP-189 in terms of corrosion resistance and edge retention. However, sharpening S110V is more difficult than sharpening ZDP-189. S110V knives are usually more expensive.

ZDP 189 vs. VG10

The latter is also a type of high-end steel. However, it is less hard and has a lower edge retention ability than ZDP-189. However, it wins over ZDP 189 in terms of corrosion resistance, toughness, and ease of sharpening.

Top ZDP-189 Knives

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So, is ZDP-189 Steel Good?

ZDP-189’s hardness level is awesome to ensure wear resistance, longer-lasting edge retention than usual, and less vulnerability to deformation. It is also resistant to corrosion if you keep it dry after using it. Be ready to spend a bit more, if you want a ZDP-189 knife though.